CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority, as appropriate, to U.S. Serial No. 63/012,151, titled “TRACKING AND TESTING FOR VIRAL OR OTHER INFECTION” and filed April 18, 2020; U.S. Serial No. 63/023,846, titled “TRACKING AND TESTING FOR VIRAL OR OTHER INFECTION” and filed May 12, 2020; and U.S. Serial No. 63/114,893, titled “TRACKING AND TESTING FOR VIRAL OR OTHER INFECTION” and filed November 17, 2020, the disclosures of which are hereby incorporated by reference in their entireties.

BACKGROUND

[0002] A virus is a submicroscopic infectious agent that replicates within a living host cell of another organism. When the host cell is infected by a virus, the virus causes the host cell to produce additional copies of the virus that may then infect other cells within the same organism or spread to other organisms.

[0003] When outside of a host a cell, a virus exists as an independent particle that may be referred to as a virion. Typically, a virion will include genetic material enclosed in a capsid consisting of protein and, in some cases, a lipid bilayer. The genetic material may be a molecule of deoxyribonucleic acid (DNA) or ribonucleic acid (RNA).

[0004] Various types of viruses infect all types of life forms. Viruses are responsible for causing many diseases within the human species, including the common cold, influenza, chickenpox, rabies, acquired immune deficiency syndrome (AIDS), and many others. As another example, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for the 2019-20 coronavirus pandemic, has infected humans around the world, causing the coronavirus disease 2019 (COVID- 19). The SARS-CoV-2 virus is also sometimes referred to as the 2019 novel coronavirus (2019-nCoV).

[0005] A virus may infect a host cell when a protein in the envelope binds to a receptor on the host cell. For example, the SARS-CoV-2 virus infects human cells when the spike (S) protein in the envelope binds to the angiotensin-converting enzyme 2 (ACE2) (ACE2 is also sometimes referred to as ACE-2 in scientific literature) receptor on human cells. FIG. 1 is an illustration of the SARS-CoV-2 virus that is provided by the U.S. Center for Disease Control and created by Alissa Eckert, MS; Dan Higgins, MAMS. As can be seen in FIG. 1, the SARS-CoV-2 virus has a generally spherical envelope with numerous spike-like structures. These spikes are formed by the glycoprotein (a protein with carbohydrate groups attached to the polypeptide chain) known as the S protein of the SARS-CoV-2 virus. Other viral structural proteins include the envelope (E) protein and the membrane (M) protein in the envelope, with multiple copies of the nucleocapsid (N) protein bound to the RNA genome inside the envelope.

[0006] Once an organism is infected by a virus, it may release virion that can infect other organisms. For example, the organism may spread virion through coughing, sneezing, or even exhaling. Infected individuals may be asked or required to quarantine to prevent spreading of the virus to others. Unfortunately, quarantine is only effective in preventing the spread of virus by those individuals who have been identified as being infected.

[0007] Accurate and widespread testing is necessary to identify infected individuals so they may quarantine. Due to limits in testing resources, however, tests may only be available to a subset of individuals, such as those who are symptomatic, those who have recently traveled to hotspots (i.e. regions with a high number of known infections), or those who are known to have had contact with infected individuals. For some viruses, not all infected individuals will be symptomatic. Furthermore, some individuals may be capable of spreading the virus prior to onset of symptoms. Accordingly, if testing is provided based on severity of symptoms, infected individuals who are asymptomatic or have not yet developed symptoms that are severe enough to warrant testing may avoid quarantine and spread the virus because they were not tested. Furthermore, delays between test administration and test results may further allow infected individuals to spread the virus while waiting for test results.

[0008] In 2020, many countries around the world have instituted social distancing policies designed to reduce the transmission of SARS-CoV-2 by keeping individuals far enough apart that virions shed by an infected individual are unlikely to come in contact with uninfected individuals. These social distancing policies come at great individual and societal cost as many common activities are prohibited. [0009] A highly available, rapid, point-of-care test for SARS-CoV-2 would help to reduce the need for social distancing policies and the costs thereof. Furthermore, such a test would also prevent or decrease the spread of SARS-CoV-2, by immediately identifying infected individuals, and thus saving lives and treatment resources.

[0010] Although many of the examples in this disclosure relate to testing and tracking viral infections and more specifically, SARS-CoV-2 infection, aspects of this disclosure may be applicable to other types of infection, whether viral or caused by other types of pathogens which may infect humans or other organisms. For example, in addition to viruses, bacteria, parasites, and fungi may cause infection too.

SUMMARY

[0011] In general terms, this disclosure is directed to testing and tracking of infections agents (or pathogens). In one possible configuration and by non-limiting example, a testing device for SARS-CoV-2 is disclosed. As another non-limiting example, methods of using ACE2 to bind whole SARS-CoV-2 are disclosed.

[0012] The details of one or more aspects are set forth in the accompanying drawings and description below. Other features and advantages will be apparent from a reading of the following detailed description and a review of the associated drawings. It is to be understood that the following detailed description is explanatory only and is not restrictive of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS [0013] FIG. 1 is an illustration of SARS-CoV-2.

[0014] FIGS. 2A-2B illustrate an embodiment of a test strip according to embodiments of the present disclosure.

[0015] FIGS. 3A-3B illustrate another embodiment of a test strip according to embodiments of the present disclosure.

[0016] FIG. 4A includes an example chart illustrating example optimized viral load ranges for the first detection region and second detection region of the test strip of FIGS. 3A and 3B.

[0017] FIG. 4B includes an example chart illustrating an example of an individual’s viral load over time following infection. [0018] FIG. 5 illustrates an example method of producing monoclonal antibodies using a hybridoma cell line for use in embodiments of the test strip of FIGS. 2A-2B. [0019] FIG. 6 illustrates an example method of tracking infection so that an individual may participate in a group event using embodiments of the test strip of FIGS. 2A-2B.

[0020] FIG. 7 illustrates an example architecture of a computing device, which can be used to implement aspects according to the present disclosure.

DETAILED DESCRIPTION

[0021] Various embodiments will be described in detail with reference to the drawings, wherein like reference numerals represent like parts and assemblies throughout the several views. Reference to various embodiments does not limit the scope of the claims attached hereto. Additionally, any examples set forth in this specification are not intended to be limiting and merely set forth some of the many possible embodiments for the appended claims.

[0022] The present disclosure relates to testing and tracking infection such as viral infection. In particular, many of the examples in this disclosure relate to testing for infection by the SARS-CoV-2 virus using lateral flow assay (also referred to as lateral flow immunochromatographic assay) technology. The technologies described herein may be used, as appropriate, with sandwich lateral flow assays or competitive lateral flow assays. Although many of the examples described herein relate to a lateral flow assay, it should be understood that the techniques may be used with other types of infection tests including but not limited to immunoassays such as enzyme-linked immunosorbent assays (ELISA), flow-through tests (immunoconcentration assays), aggregation assays, western blots, and other types of immunoassays.

[0023] The term “antibody,” as used herein, includes, but is not limited to a polypeptide substantially encoded by an immunoglobulin gene or immunoglobulin genes, or fragments thereof, which specifically bind and recognize an analyte (antigen or antibody). Examples include monoclonal, mixed monoclonal (which may function like defined polyclonal antibodies), polyclonal, chimeric, humanized, and single chain antibodies, and the like. Fragments of immunoglobulins include Fab fragments and fragments produced by an expression library, including phage display. See, e.g., Paul, FUNDAMENTAL IMMUNOLOGY, 3rd Ed., 1993, Raven Press, New York, for antibody structure and terminology.

[0024] The term “epitope” means an antigenic determinant capable of specific binding to an antibody. Epitopes usually consist of surface groupings of molecules such as amino acids or sugar side chains and usually have specific three-dimensional structural characteristics, as well as specific charge characteristics.

[0025] The terms “specifically binds to” and “specifically immunoreactive with” refer to a binding reaction that is determinative of the presence of the target analyte in the presence of a heterogeneous population of proteins and other biologies. Thus, under designated assay conditions, the specified binding moieties bind preferentially to a particular target analyte and do not bind in a significant amount to other components present in a test sample. Specific binding to a target analyte under such conditions may require a binding moiety that is selected for its specificity for a particular target analyte. A variety of immunoassay formats may be used to select antibodies specifically immunoreactive with a particular antigen. For example, solid-phase ELISA immunoassays are routinely used to select monoclonal antibodies specifically immunoreactive with an analyte. See Harlow and Lane, ANTIBODIES: A LABORATORY MANUAL, Cold Springs Harbor Publications, New York, (1988) for a description of immunoassay formats and conditions that can be used to determine specific immunoreactivity. Typically, a specific or selective reaction will be at least twice background signal to noise and more typically more than 10 to 100 times greater than background.

[0026] A “protein” refers to a biopolymer composed of amino acid or amino acid analog subunits, typically some or all of the 20 common L-amino acids found in biological proteins. Although “protein” commonly refers to a relatively large polypeptide, e.g., containing 100 or more amino acids, and “peptide” to smaller polypeptides, the terms are used interchangeably herein. That is, the term protein may refer to a larger polypeptide, as well as to a smaller peptide, and vice versa.

[0027] An “immunologically reactive fragment” of a protein refers to a portion of the protein which is immunologically reactive with a binding partner, e.g., antibody, which is immunologically reactive with the protein itself.

[0028] As used herein, a “receptor” of a protein refers to a portion of the protein which is reactive with a binding partner (e.g., an antibody, another protein, or a virus). [0029] “Specificity”, as it relates to the assay method of the invention, refers to the ability of the assay to specifically detect a specific infection such as SARS-CoV-2 infection.

[0030] “Reliability”, as it relates to the assay method of the invention, refers to the percentage of a population that is detected as a true positive. For example, at least 80% reliability means that the assay will detect infection in at least 80% of the subjects tested who are in fact infected, as determined, for example, by a confirmatory test such as viral culture or polymerase chain reaction (PCR). The term is also used interchangeably with “sensitivity.”

[0031] FIGS. 2A and 2B show an example test strip 100 that may be used to detect the presence of SARS-CoV-2 in a sample. FIG. 2A is a top view and FIG. 2B is a side view. The test strip 100 may be a lateral flow assay test strip. The test strip 100 includes an elongated porous matrix 102. The matrix 102 may be supported by a solid support 103. The matrix 102 has an upstream end 104 and a downstream end 105. Fluid will flow through the matrix 102 from the upstream end 104 toward the downstream end 105.

[0032] The test strip 100 may also include a porous-material pad 106 that is disposed on the matrix 102 near (or proximal to) the upstream end 104. The pad 106 includes a sample-loading region 107. The test strip 100 is designed to receive sample fluid from an individual at the sample-loading region 107 and to indicate whether the received sample fluid contains SARS-CoV-2 or parts thereof (e.g., proteins or protein fragments from SARS-CoV-2). For example, the sample fluid may include mucus retrieved from a nasopharyngeal swab from an individual. As another example, the sample fluid may include saliva from the individual. The sample fluid may also include blood, urine, phlegm, sputum, sweat, serum, feces, semen, or vaginal fluid. In some embodiments, the sample fluid is mixed with a buffer agent before being applied to the sample-loading region 107.

[0033] The pad 106 also includes a reaction region 110 that is positioned downstream from the sample-loading region 107. The reaction region 110 includes a mobile, labeled binding agent that is specifically selected to bind to SARS-CoV-2. As used herein, the binding agent is described as mobile because it is free to flow through the matrix 102 with the sample fluid. Examples of the binding agent include monoclonal antibodies selected to specifically bind to SARS-CoV-2, polyclonal antibodies selected to specifically bind to SARS-CoV-2, mixed monoclonal antibodies selected to specifically bind to SARS-CoV-2, and ACE2 proteins or portions of the ACE2 protein that includes the receptor to which the S protein of SARS-CoV-2 binds such as the ACE2 Fc (i.e., ACE2 or a portion thereof attached to (e.g., via chimeric fusion) the fragment crystallizable region of an antibody).

[0034] As used herein, the term mixed monoclonal antibodies refers to a mixture of multiple different monoclonal antibodies. The mixed monoclonal antibodies may each have been selected for specifically binding to SARS-CoV-2. For example, mixed monoclonal antibodies may include two or more of the following: antibodies selected to specifically bind to the S protein of SARS-CoV-2, antibodies selected to specifically bind to the M protein of SARS-CoV-2, antibodies selected to specifically bind to the E protein of SARS-CoV-2, antibodies selected to specifically bind to the N protein of SARS-CoV-2, and antibodies selected to specifically bind to sugars expressed by SARS-CoV-2. The mixed monoclonal antibodies may include defined- ratio mixed monoclonal antibodies wherein the monoclonal antibodies included in the mixture are included in a specified ratio. In some embodiments, the specified ratio is selected based on evaluating various ratios to identify a ratio that results in increased binding to the SARS-CoV-2 in test samples. For example, a specific ratio may be identified through testing based on testing to identify a ratio that increases sensitivity and specificity.

[0035] As described elsewhere herein, the binding agent is labeled. The binding agent may include various types of labels including visible labels, fluorescent labels, and other types of labels.

[0036] Additionally, the reaction region 110 may also include mobile, labeled control agents. These control agents are also mobile and will flow through the matrix 102 when the sample fluid is applied. The control agent may include control antibodies that are not intended (or selected) to bind to SARS-CoV-2.

[0037] As seen in FIG. 2B, the pad 106 is attached to the upper surface of the matrix 102 and communicates therewith by capillary fluid flow. Thus, the sample fluid applied to the sample-loading region 107 flows into the pad 106 and through the pad 106 into the reaction region 110. Here, the sample fluid causes the release of the mobile binding agent, where the mobile binding agent may react with any SARS- CoV-2, forming a mobile, labeled virus complex that can migrate through the pad 106 and into the matrix 102 by capillary flow. The mobile, labeled virus complex may, for example, include a mobile binding agent bound to the virus or a portion of the virus. [0038] The matrix 102 includes a detection region 112 and a control region 114 that are positioned downstream from the reaction region 110. The detection region 112 includes a capture reagent that is fixedly deposited in the matrix 102. Although alternatives are possible, the detection region 112 may include capture reagent deposited in a stripe (or line). The control region 114 includes a control reagent that is fixedly deposited in the matrix 102. Although alternatives are possible, the control region 114 may include control reagent deposited in a stripe (or line). In FIGS. 2A- 2B, the capture reagent and control reagent are deposited as stripes crossing the width of the matrix 102. However, it should be understood that the capture reagent and control reagent may be deposited in any suitable arrangement.

[0039] In this example, the test strip 100 also includes an absorbent pad 118 that is disposed on the matrix 102 at or near the downstream end 105. Some embodiments may include a tape or another type of covering that is disposed on top of the absorbent pad 118 to provide a gripping surface or handle for the test strip 100. The purpose of the pad 118 is to serve as an absorbent reservoir, to continue to draw sample fluid from the sample-loading region 107 through the detection region 112 and the control region 114. Some embodiments may include other means to draw sample fluid through the matrix 102 in addition to or instead of the absorbent pad 118.

[0040] As the sample fluid flows downstream through the matrix 102 from the reaction region 110 to the absorbent pad 118, the capture reagent will bind to at least a portion of the mobile, labeled virus complex, if present, fixing the mobile, labeled virus complex to the detection region 112. The presence of the mobile virus complex fixed in the detection region 112 may then be potentially detected visually or using a specialized reader. The presence of the mobile virus complex would be indicative that the sample fluid contained SARS-CoV-2, indicating that the individual the sample was taken from was currently suffering from a SARS-CoV-2 infection.

[0041] Additionally, as the sample fluid flows downstream through the matrix 102 from the reaction region 110 to the absorbent pad 118, the control reagent will bind to some of the mobile, labeled control agents, fixing the labeled control agents in the control region 114. The presence of the labeled control agents in the control region 114 may then be potentially detected visually or using a specialized reader. The presence of the labeled control agents in the control region 114 would indicate the sample fluid had flowed to control region 114 and therefore also had passed through the detection region 112 (i.e., because the control region 114 is downstream from the detection region 112). Detection of control agents fixed in the control region 114 when labels are not detected in the detection region 112, may indicate the test has completed without detecting the presence of SARS-CoV-2, indicating the individual from whom the sample was taken is not currently infected with SARS-CoV-2. As an example, the control region 114 may include fixed antibodies from a specific first species, and the labeled control agents may be antibodies from a second species that are directed against the first species. For example, the labeled control agent may be labeled chicken antibodies and the control region fixedly-deposited antibodies may be antibodies from a donkey that bind to chicken antibodies (i.e., donkey anti-chicken antibodies).

[0042] The matrix 102 may be formed of a glass fiber filter paper which allows a sample received at sample-loading region 107 to flow by capillary action along the longitudinal axis of test strip 100. Other porous materials, such as the non-bibulous matrix materials described elsewhere herein may also be used. The solid support 103 may be formed of a nitrocellulose membrane. Other suitable materials, such as paper, nylon membranes, glass, plastic, metal, and the like may also be used.

[0043] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled ACE2 receptors, and the detection region 112 includes fixed ACE2 receptors. Because SARS-CoV-2 includes numerous S proteins on its envelope, a single SARS-CoV-2 virion can bind to both the mobile, labeled ACE2 receptor from the reaction region 110 and fixed ACE2 receptors in the detection region 112. The ACE2 receptor may be the entire human ACE2 protein or a portion of the ACE2 protein that includes the receptor. One or both of the reaction region 110 or the detection region 112 may include ACE2 Fc. [0044] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled monoclonal antibodies for SARS-CoV-2, and the detection region 112 includes fixed monoclonal antibodies from mixed monoclonal antibodies for SARS-CoV-2.

[0045] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled antibodies from mixed monoclonal antibodies for SARS-CoV-2, and the detection region 112 includes fixed antibodies from mixed monoclonal antibodies for SARS-CoV-2.

[0046] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled antibodies from mixed monoclonal antibodies for SARS-CoV-2, and the detection region 112 includes fixed monoclonal antibodies (e.g., a single type of monoclonal antibodies) for SARS- CoV-2.

[0047] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled antibodies from a mixture of multiple monoclonal antibodies for SARS-CoV-2, and the detection region 112 includes fixed monoclonal antibodies for SARS-CoV-2.

[0048] To be clear, all possible combinations of using ACE2 (or portions thereol), monoclonal antibodies, mixed monoclonal antibodies, and polyclonal antibodies in either or both of the reaction region 110 and the detection region 112 are contemplated herein. For example, the reaction region 110 and the detection region 112 may both include combinations of ACE2 and mixed monoclonal antibodies. In some embodiments, the detection region 112 may include multiple sub-regions. For example, one sub-region may primarily or entirely include monoclonal antibodies that bind to E proteins of SARS-CoV-2, another sub-region may primarily or entirely include monoclonal antibodies that bind to M proteins of SARS-CoV-2, another sub- region may primarily or entirely include monoclonal antibodies that bind to N proteins of SARS-CoV-2, and another sub-region may primarily or entirely include ACE2 or monoclonal antibodies that bind to S proteins of SARS-CoV-2. Some embodiments do not include all of these sub-regions. The sub-regions may be arranged as stripes or in other shapes or patterns. Image processing techniques may be used to identify which sub-regions of the detection region 112 captured the most labeled viral material or to determine relative proportions of captured viral material between sub-regions. This information may be useful in characterizing the status of an infection in the tested individual.

[0049] In at least some embodiments, the test strip 100 is designed for the detection of SARS-CoV-2, the reaction region 110 includes mobile, labeled monoclonal antibodies for SARS-CoV-2, and the detection region 112 includes fixed ACE2 receptors. In another embodiment, the reaction region 110 includes mobile, labeled ACE2 receptors and the detection region 112 includes fixed monoclonal antibodies for SARS-CoV-2. The monoclonal antibodies may be a single type of monoclonal antibodies. The monoclonal antibodies may include a mixture of multiple types of monoclonal antibodies.

[0050] The antibodies for SARS-CoV-2 may be derived using the methods described elsewhere herein. In some embodiments, the antibodies for SARS-CoV-2 are derived using whole (actual) virus that is clinically captured from an infected individual. In some embodiments, the antibodies for SARS-CoV-2 are derived using a clinical virus prepared from genetic sequence information for SARS-CoV-2.

[0051] An example method for detecting SARS-CoV-2 infection includes collecting a sample from an individual. The sample may include a nasopharyngeal sample, saliva sample, or another type of sample. The method may also include applying the sample to a sample-loading region of a lateral flow assay test strip. The lateral flow assay may include mobile, labeled binding agents that specifically bind to SARS-CoV-2 in a reaction region of the test strip. The labeled binding agents may include one or more of human ACE2 protein, a portion of the ACE2 protein that includes the receptor that the SARS-CoV-2 spike protein binds to, monoclonal antibodies that specifically bind to SARS-CoV-2, polyclonal antibodies that specifically bind to SARS-CoV-2, and a mixture of multiple monoclonal antibodies that specifically bind to SARS-CoV-2.

The lateral flow assay may also include fixed binding agents that specifically bind to SARS-CoV-2 in a detection region of the test strip. The fixed binding agents may include one or more of human ACE2 protein, a portion of the ACE2 protein that includes the receptor that the SARS-CoV-2 spike protein binds to, monoclonal antibodies that specifically bind to SARS-CoV-2, polyclonal antibodies that specifically bind to SARS-CoV-2, and mixed monoclonal antibodies that specifically bind to SARS-CoV-2. The method also includes detecting whether the labeled binding agents are present in the detection region of the test strip. Detecting whether the labeled binding agents are present may include a visual inspection of the detection region or inspection of the detection region with a specialized reader. The method may also include determining that the individual is or is not infected based on the presence of the labeled binding agents in the detection region.

[0052] Some embodiments of the test strip include an additional integrity control region that includes fixed integrity control antibodies that are selected to specifically bind to protein that is expected to be regularly present in a sample from an individual. In such an embodiment, the reaction region may include mobile, labeled integrity control antibodies that also specifically bind to that protein. In this manner, the integrity control region will capture labeled integrity control antibodies when the fluid flow includes a properly collected sample. For example, the labeled control antibodies and fixed integrity control antibodies may be selected to specifically bind to mucin, a glycoprotein constituent of mucus.

[0053] Although not shown in FIGS. 2A and 2B, the test strip may be contained within a housing. The housing may be formed from plastic and may include a window to allow application of the sample fluid to the sample-loading region 107. The housing may be at least partially transparent to permit viewing of the detection region 112 and the control region 114.

[0054] FIG. 3A and 3B show an example test strip 200 that may be used to detect the presence of SARS-CoV-2 in a sample. FIG. 3 A is a top view and FIG. 3B is a side view. The test strip 200 may be similar to the test strip 100 that is illustrated and described with respect to at least FIGS. 2A and 2B. In this example, the test strip 200 includes a first detection region 212 and a second detection region 213. The first detection region 212 may include a different arrangement of capture reagents than the second detection region 213.

[0055] Like the test strip 100, the test strip 200 may be a lateral flow assay test strip. The test strip 200 includes the elongated porous matrix 102 that is supported by the solid support 103. The test strip 200 may also include the porous-material pad 106 that is disposed on the matrix 102 near (or proximal to) the upstream end 104.

[0056] The pad 106 includes the sample-loading region 107. The pad 106 also includes a reaction region 210 that is positioned downstream from the sample-loading region 107. The reaction region 210 may be similar to the previously described reaction region 110.

[0057] The reaction region 210 includes one or more mobile, labeled binding agents that are specifically selected to bind to SARS-CoV-2. The reaction region 210 may include a mixture of multiple binding agents. For example, the reaction region 210 may include a first binding agent and a second binding agent. The reaction region 210 may include multiple binding agents in equal or approximately equal proportion. In some implementations, the reaction region 210 include the first binding agent and the second binding agent in a pre-defmed ratio. In some implementations, the first binding agent and the second binding agent incorporate labels that cannot be distinguished from one another (e.g., the labels are of the same type, are formed from the same material, are visually indistinct, or are otherwise indistinct). In some implementations, the first binding agent and the second binding agent incorporate labels that can be distinguished from one another (e.g., different types or labels or labels having properties that are visually distinct or otherwise distinct).

[0058] Although alternatives are possible, the first binding agent may be a specific monoclonal antibody that is selected to specifically bind to SARS-CoV-2 forming a first mobile, labeled virus complex. In some implementations, the second binding agent may include mixed monoclonal antibodies that are selected to specifically bind to SARS-CoV-2 forming a second mobile, labeled virus complex. The second binding agent and second mobile, labeled virus complex may also be referred to as an alternate binding agent and an alternate mobile, labeled virus complex. In some implementations, the second binding agent includes defined-ratio mixed monoclonal antibodies.

[0059] In some implementations, the first binding agent and the second binding agent each include one or more of monoclonal antibodies selected to specifically bind to SARS-CoV-2, polyclonal antibodies selected to specifically bind to SARS-CoV-2, mixed monoclonal antibodies selected to specifically bind to SARS-CoV-2, and ACE2 proteins or portions of the ACE2 protein that includes the receptor to which the S protein of SARS-CoV-2 binds such as the ACE2 Fc (i.e., ACE2 or a portion thereof attached to (e.g., via chimeric fusion) the fragment crystallizable region of an antibody).

[0060] Additionally, the reaction region 210 may also include mobile, labeled control agents. These control agents are also mobile and will flow through the matrix 102 when the sample fluid is applied. The control agent may include control antibodies that are not intended (or selected) to bind to SARS-CoV-2.

[0061] The matrix 102 also includes a first detection region 212, a second detection region 213, and the control region 114 that are all positioned downstream from the reaction region 210. The first detection region 212 includes a first capture reagent that is fixedly deposited in the matrix 102. The second detection region 213 includes a second capture reagent that is fixedly deposited in the matrix 102. The second detection region 213 and second capture reagent may also be referred to as an alternate detection region and an alternate capture reagent respectively.

[0062] The first capture reagent may be selected to specifically bind to the first mobile, labeled virus complex (i.e., the mobile, labeled virus complex formed by the combination of virion and the first binding agent of the reaction region). The second capture reagent may be selected to specifically bind to the second mobile, labeled virus complex (i.e., the mobile, labeled virus complex formed by the combination of virion and the first binding agent of the reaction region). The first capture reagent may be different than the second capture reagent.

[0063] The first capture reagent may include one or more of monoclonal antibodies selected to specifically bind to the first mobile, labeled virus complex, polyclonal antibodies selected to specifically bind to the first mobile, labeled virus complex, mixed monoclonal antibodies selected to specifically bind to the first mobile, labeled virus complex, and ACE2 proteins or portions of the ACE2 protein that includes the receptor to which the first mobile, labeled virus complex binds such as the ACE2 Fc. Similarly, the second capture reagent may include one or more of monoclonal antibodies selected to specifically bind to the second mobile, labeled virus complex, polyclonal antibodies selected to specifically bind to the second mobile, labeled virus complex, mixed monoclonal antibodies selected to specifically bind to the second mobile, labeled virus complex, and ACE2 proteins or portions of the ACE2 protein that includes the receptor to which the second mobile, labeled virus complex binds such as the ACE2 Fc.

[0064] In some implementations, the first capture reagent is selected based on empirical testing of multiple candidate reagents to identify a reagent that selectively binds to the first mobile, labeled virus complex. For example, multiple reagents may be tested for binding with the first mobile, labeled virus complex. A reagent that binds to more than a threshold quantity (or percentage) of the first mobile, labeled virus complex may be selected as the first capture reagent. In some implementations, the candidate reagent that binds to the greatest quantity (or percentage) of the first mobile, labeled virus complex may be selected as the first capture reagent.

[0065] Similarly, in some implementations, the second capture reagent is selected based on empirical testing of multiple candidate reagents to identify a reagent that selectively binds to the second mobile, labeled virus complex. For example, multiple reagents may be tested for binding with the second mobile, labeled virus complex. A reagent that binds to more than a threshold quantity (or percentage) of the second mobile, labeled virus complex may be selected as the second capture reagent. In some implementations, the candidate reagent that binds to the greatest quantity (or percentage) of the second mobile, labeled virus complex may be selected as the second capture reagent.

[0066] In some implementations, the first capture reagent and second capture reagent are also selected based on the specificity of their binding to the first mobile, labeled virus complex and the second mobile, labeled virus complex. For example, the first capture reagent may be selected based on its binding to the first mobile, labeled virus complex and its lack of binding to the second mobile, labeled virus complex.

Similarly, the second capture reagent may be selected based on its binding to the second mobile, labeled virus complex and its lack of binding to the first mobile, labeled virus complex. In some implementations, the first capture reagent and the second capture reagent are selected based on their lack of binding to the control agent used in the reaction region 210.

[0067] Although alternatives are possible, the first detection region 212 may include the first capture reagent deposited in a stripe (or line) and the second detection region 213 may include the second capture reagent deposited in another stripe (or line). In FIGS. 3A-3B, the first capture reagent and second capture reagent are deposited as stripes crossing the width of the matrix 102. However, it should be understood that the capture reagent and control reagent may be deposited in any suitable arrangement. [0068] In this example, the test strip 200 also includes the absorbent pad 118 that is disposed on the matrix 102 at or near the downstream end 105. Some embodiments may include a tape or another type of covering that is disposed on top of the absorbent pad 118 to provide a gripping surface or handle for the test strip 100. A purpose of the pad 118 is to serve as an absorbent reservoir, to continue to draw sample fluid from the sample-loading region 107 through the first detection region 212, the second detection region 213, and the control region 114. Some embodiments may include other means to draw sample fluid through the matrix 102 in addition to or instead of the absorbent pad 118.

[0069] As the sample fluid flows downstream through the matrix 102 from the reaction region 210 to the absorbent pad 118, the first capture reagent will bind to at least a portion of the first mobile, labeled virus complex, if present, fixing the first mobile, labeled virus complex to the first detection region 212, and the second capture reagent will bind to at least a portion of the second mobile, labeled virus complex, if present, fixing the second mobile, labeled virus complex to the second detection region 213. The presence of the first mobile virus complex fixed in the first detection region 212 may then be potentially detected visually or using a specialized reader. Similarly, the presence of the second mobile virus complex fixed in the second detection region 213 may then be potentially detected visually or using a specialized reader. The presence of the first mobile virus complex or the second mobile virus complex would be indicative that the sample fluid contained SARS-CoV-2, indicating that the individual the sample was taken from was carrying SARS-CoV-2 at the time the sample was taken.

[0070] Additionally, as the sample fluid flows downstream through the matrix 102 from the reaction region 210 to the absorbent pad 118, the control reagent will bind to some of the mobile, labeled control agents, fixing the labeled control agents in the control region 114. The presence of the labeled control agents in the control region 114 would indicate the sample fluid had flowed to control region 114 and therefore also had passed through the first detection region 212 and the second detection region 213 (i.e., because the control region 114 is downstream from both the first detection region 212 and the second detection region 213). Detection of the labeled control agents fixed in the control region 114 when labels are not detected in either the first detection region 212 or the second detection region 213, may indicate the test has completed without detecting the presence of SARS-CoV-2, indicating the individual was not carrying SARS-CoV-2 at the time the sample was taken.

[0071] In some implementations, the combination of the first binding agent and the first capture reagent are selected for higher sensitivity to a first viral load level and the combination of the second binding agent and the second capture reagent are selected for higher sensitivity to a second viral load level. For example, the first viral load level may be a lower viral load and the second viral load level may be a higher viral load. The lower viral load may occur earlier in an infection or in individuals who express less of the virus during an infection. The higher viral load may occur earlier in an infection or in individuals who express more of the virus during an infection. In some implementations, in addition to or as an alternative to using different agents, the first binding agent and the first capture reagent may be provided in different quantities or ratios than the second binding agent and the second capture agent.

[0072] In some implementations, the combination of the second binding agent and the second capture agent may be selected (or optimized) to detect the higher viral load and so the lower viral load may not be reliably detected in the second detection region 213. Similarly, in some implementations, the combination of the first binding agent and the first capture agent may be selected (or optimized) to detect the lower viral load and so the higher viral load may not be reliably detected in the first detection region 212. For example, the presence of the higher viral load may result in a large quantity of mobile viral complexes that interfere (e.g., block each other from binding) with the first capture reagent binding to the mobile viral complexes.

[0073] FIG. 4A includes an example chart 400A that illustrates example optimized viral load ranges for the first detection region 212 and the second detection region 213. As can be seen in this example, the first detection region 212 is optimized for a lower viral load range and the second detection region 213 is optimized for a higher viral load range. Even outside of their optimized viral load ranges, the first detection region 212 and second detection region 213 may capture labeled mobile viral complexes in some embodiments.

[0074] Visual inspection or image processing techniques may be used to quantify the amount of the first mobile virus complex in the first detection region 212 and the amount of the second mobile virus complex in the second detection region 213. The image processing techniques may be implemented using a specialized test reader and software instructions that are stored on and executed by a computing device such as the computing device 950, which is illustrated and discussed with respect to at least FIG. 7. The image processing techniques may, for example, identify which of the first detection region 212 and the second detection region 213 captured the most labeled viral material or to determine relative proportions of captured viral material between the first detection region 212 and the second detection region 213.

[0075] In some implementations, an estimate of viral load in a sample may be determined based on the quantified amounts of the first mobile virus complex and the second mobile virus complex. The estimate of viral load may then be used to infer a viral status or a duration of time that has elapsed between the individual being infected and the sample being collected. The duration of elapsed time may be useful for contact tracing purposes (e.g., for identifying others who may have been exposed to the virus by the individual being tested). The viral load may also be useful in determining appropriate care or treatment recommendations for an infected individual.

[0076] FIG. 4B includes an example chart 400B that illustrates an example of an individual’s viral load over time following an infection at a time tO. In this example, the individual’s viral load reaches a level within the optimized viral load level range for the first detection region 212 at a time tl. The individual’s viral load reaches a level within the optimized viral load level region for the second detection region 213 at a time t2. As can be seen in this figure, the time tl occurs earlier than the time t2, which means the first detection region 212 may be optimized to detect virus earlier in an individual’s infection than the second detection region 213. This earlier detection may allow an individual to begin quarantining (or isolating) sooner so as to prevent (or minimize) the chance of spreading the infection to others. This earlier detection may also allow the individual to begin any recommend treatment or care protocols sooner, potentially resulting in a better outcome for the infected individual. In some implementations, the optimized range for first detection region 212 may include a viral load that is similar to the level of detectability for a PCR test.

[0077] An example method for detecting SARS-CoV-2 infection includes collecting a sample from an individual. The sample may include a nasopharyngeal sample, saliva sample, or another type of sample. The method may also include applying the sample to a sample-loading region of a lateral flow assay test strip. The lateral flow assay test strip may include first mobile, labeled binding agents and second mobile, labeled binding agents that specifically bind to SARS-CoV-2 in a reaction region of the test strip. The first mobile, labeled binding agent may bind to SARS-CoV-2 virion to form a first mobile, labeled virus complex. The second mobile, labeled binding agent may bind to SARS-CoV-2 virion to form a second mobile, labeled virus complex. The lateral flow assay may also include fixed first capture agents that specifically bind to the first mobile, labeled virus complex in a first detection region of the test strip and fixed second capture agents that specifically bind to the second mobile, labeled virus complex in a second detection region of the test strip. The method also includes detecting whether the labeled binding agents are present in the first detection region and the second detection region of the test strip. Detecting whether the labeled binding agents are present may include a visual inspection of the first detection region and the second detection region or inspection of the first detection region and the second detection region with a specialized reader. The method may also include determining that the individual is or is not infected based on the presence of the labeled binding agents in the first detection region or second detection region. The method may also include quantifying amounts of labeled binding agents in the first detection region and the second detection region. The method may also include estimating a viral load for the individual based on the quantified amounts. In some implementations, the method includes inferring a viral status or duration of infection for the individual based on the quantified amounts.

[0078] In some embodiments, the labels attached to the mobile binding agents in the reaction region are selected to be visible such that, in sufficient quantity, the labels can be seen with the human eye. In some embodiments, the detection region and the control region may be shaped or arranged to provide an encoded result such that the result (i.e., the infection status of the individual) is not apparent from viewing the detection region and control region. Instead, an image may be captured with, for example, a smartphone. The smartphone may then communicate with an external server to decipher the results of the test. In some implementations, a key may be associated with each test strip and may be used in combination with the image to decipher the results. These encoded results will help secure the privacy of the individual as well as aid in infection tracking efforts.

[0079] In some embodiments, a porous or fibrous test strip that allows for capillary flow therethrough includes, in an upstream-to-downstream direction, a sample loading region, a reaction region, and a detection region. The sample-loading region may be simply an area on the strip to which sample is added. The reaction region contains anon-immobilized (or mobile) labeled reagent capable of binding to sample analyte (e.g., a protein of SARS-CoV-2) to form a labeled mobile complex (i.e., a complex capable of migrating through the test strip, typically by capillary flow, in a downstream direction toward the detection region). Where the analyte is SARS-CoV- 2, the labeled reagent may be an antibody to SARS-CoV-2, as detailed below. Typically, the reagent is added to the strip in soluble form and allowed to dry, such that upon wetting, with application of sample to the strip, the dried reagent can enter the soluble phase and migrate through the test strip medium. [0080] The detection region contains an immobilized capture reagent capable of binding to the analyte moiety of the mobile complex, to immobilize the labeled complex in this zone, while labeled, but non-complex reagent passes through the zone with the moving sample-fluid medium. The immobilized binding reagent may be covalently bound to the strip matrix or tightly bound by non-covalent linkage, e.g., electrostatic or dispersion forces. In any event, the immobilization is sufficient to allow the binding reagent to capture and immobilize the labeled complex as sample fluid migrates through the detection region. Where the analyte is SARS-CoV-2, the immobilized binding reagent may be an antibody capable of binding specifically to SARS-CoV-2 in the complex form. That is, the labeled antibody and immobilized capture antibody may recognize separate and different binding sites on SARS-CoV-2. [0081] The strip may further include a second capture zone at which non-complexed labeled reagent may be captured, to serve as a control to confirm that labeled reagent is being released from the reaction region for movement through the strip, as well as the labeled reagent is being captured by immobilized capture agents. Where the labeled reagent is a labeled antibody, the control capture agent is preferably an antibody that is immunoreactive with the labeled antibody. Thus, for example, if the labeled antibody is a mouse monoclonal antibody, the control capture reagent could be a rabbit anti-mouse antibody. The control capture reagent may consist of an anti antibody potentially obtained from a species that is different from the species used to raise the antibodies of the labeled reagent and the capture reagent. Thus, if the labeled reagent and the capture reagent were obtained from rabbit, then the antibody deposited at the control region may be goat anti-mouse IgG, sheep anti-mouse IgG, pig anti-mouse IgG, and the like.

[0082] There are a wide variety of labels which may be used with a binding moiety (antibody or antigen) to form a labeled reagent. The choice of the label depends on the sensitivity required, ease of conjugation with the binding moiety, stability requirements, available instrumentation, and disposal provisions. Labels of the present invention may be soluble or particulate, metallic, organic, or inorganic, and may include spectral labels such as green fluorescent protein, fluorescent dyes (e.g., fluorescein and its derivatives, rhodamine and its derivatives, biotin, avidin, and streptavidin), ir chemiluminescent compounds (e.g., luciferin and luminol); and enzymes (e.g., horseradish peroxidase, alkaline phosphatase, etc.), spectral calorimetric labels such as colloidal gold, or carbon particles, or colored glass or plastic (e.g. polystyrene, polypropylene, latex, etc.) beads.

[0083] The label can be coupled directly or indirectly to a component of the binding moiety according to methods well known in the art, such as those described in U.S. Pat. Nos. 4,863,875 and 4,373,932, each of which is incorporated herein by reference. Non-radioactive labels are often attached by indirect means. Generally, a ligand molecule (e.g., biotin) is covalently bound to the binding moiety. The ligand then binds to an anti-ligand (e.g., streptavidin) molecule which is either inherently detectable or is covalently bound to a signal system such as a detectable enzyme, a fluorescent compound, or a chemiluminescent compound. The label may be attached to the binding moiety by a chemical linker. Linker domains are typically polypeptide sequences, such as poly-gly sequences of between about 5 to 200 amino acids. Preferred linkers are often flexible amino acid sub-sequences. Such flexible linkers are known to persons skilled in the art. For example, poly(ethylene glycol) is available commercially (Shearwater Polymers, Inc. Huntsville, AL). The detection moiety can also be conjugated directly to the signal-generating compound, e.g., by conjunction with an enzyme or fluorophore.

[0084] The presence of a label can be detected by inspection, or a detector that monitors a particular probe or probe combination. Typical detectors include spectrophotometers, phototubes and photodiodes, microscopes, scintillation counters, cameras, film and the like, as well as combinations thereof. Examples of suitable detectors are widely available from a variety of commercial sources known to persons skilled in the art.

[0085] In at least some embodiment of the present disclosure, labels are non radioactive and are readily detected without the use of sophisticated instrumentation. For example, the labels may yield a visible signal that is immediately discernible upon visual inspection, or by fluorescence detection. The labels may include those that may be observed as: 1) chemiluminescence (using horseradish peroxidase and/or alkaline phosphatase with substrates that produce photons as breakdown products); 2) color change (colloidal gold, which produces a colored precipitate with the immuno- reactive event), and 3) fluorescence (using, e.g., fluorescein, and other fluorescent tags). In one embodiment, colloidal gold is used as the label and the label is directly conjugated to the binding moiety (the antibody or antigen). When gold is used as the label, the reaction of labeled reagent-analyte complex with the capture reagent results in the appearance of a red colored deposit. As will be appreciated by one of skill in the art, the color that appears upon the reaction of the complex with the capture reagent immobilized at the capturing zone will depend on the label used.

[0086] In an embodiment of the assay, the capture and control capture reagents are immobilized on a solid substrate. There are a variety of solid supports known to the art which are suitable for use in embodiments. For instance, the solid support may be beads, membranes (e.g., nitrocellulose), microtiter wells (e.g., PVC or polystyrene), strings, plastic, strips, or any surface onto which antibodies may be deposited or immobilized. In addition, a wide variety of organic and inorganic polymers, both natural and synthetic, may be employed as the material for the solid surface. Illustrative polymers include polyethylene, polypropylene, poly(4-methylbutene), polystyrene, polymethacrylate, poly(ethylene terephthalate), rayon, nylon, poly(vinyl butyrate), polyvinylidene difluoride (PVDF), silicones, polyformaldehyde, cellulose, cellulose acetate, nitrocellulose, and the like. Other materials that may be employed include paper, glasses, ceramics, metals, metalloids, semiconductive materials, cements or the like. In addition, substances that form gels, such as proteins (e.g., gelatins), lipopolysaccharides, silicates, agarose and polyacrylamides can be used. Polymers which form several aqueous phases, such as dextrans and polyalkylene glycols or surfactants, such as phospholipids or long chain (12-24 carbon atoms) alkyl ammonium salts and the like are also suitable.

[0087] The manner of linking a wide variety of compounds to various surfaces is well known and is amply illustrated in the literature. See, for example, IMMOBILIZED ENZYMES, Ichiro Chibata, Halsted Press, New York, 1978, and Cuatrecasas, 1970, the disclosures of which are incorporated herein by reference. The capturing and control reagents may be covalently bound or non-covalently attached through nonspecific bonding. If covalent bonding between a compound and the surface is desired, the surface will usually be polyfunctional or be capable of being poly functionalized. Functional groups which may be present on the surface and used for linking can include carboxylic acids, aldehydes, amino groups, cyano groups, ethylenic groups, hydroxyl groups, mercapto groups and the like. In addition to covalent bonding, various methods for noncovalently binding an assay component can be used. Noncovalent binding is typically nonspecific absorption of a compound to the surface. Typically, the surface is blocked with a second compound to prevent nonspecific binding of labeled assay components.

[0088] The antibodies can be either monoclonal antibodies, mixed monoclonal antibodies, or polyclonal antibodies. Single chain antibodies and fragments of antibodies are also useful as binding moieties. Thus, the term “antibody,” as used herein, also includes single chain antibodies and antibody fragments either produced by the modification of whole antibodies or those synthesized de novo using recombinant DNA methodologies.

[0089] Antibodies used in the embodiments of the assay disclosed herein may be obtained by conventional antibody development techniques. See, e.g., Harlow and Lane, eds., ANTIBODIES; A LABORATORY MANUAL, Coldspring Harbor Laboratory, Coldspring, N.Y. Suitable inoculant for preparing the antibodies includes but not limited to the whole virus obtained from a clinical sample from an infected individual or a recombinant virus or virus protein. Suitable antibodies should be immunoreactive under aqueous and ionic and non-ionic detergent buffer conditions. [0090] Polyclonal antibodies may be prepared, e.g., as described in Harboe and Ingild, Scand. J. Immun. 2 (Suppl. 1), p. 161-164, (1973). More specifically, polyclonal antibodies can be obtained by inoculating any of various host animals, including but not limited to rabbits, mice, rats, sheep, goats and the like, with the above described inoculant in a suitable adjuvant, such as Freund’s incomplete or complete adjuvant. The inoculation may be followed by one or more booster injections at suitable intervals (e.g., one or two weeks to a month). The animals are bled regularly, for instance at weekly intervals, and the antibody is isolated from the serum.

[0091] The monoclonal antibody may be produced by use of a hybridoma cell line (e.g., as described by Kohler and Milstein, Nature 256, 1975, p. 495, or U.S. Pat. No. 4,707,442 to Alderete) as shown in FIG. 5. Several myeloma cell lines may be used for the production of fused cell hybrids, including P3/X63-Ag 8, P3/NSI/l-Ag 4-1, Sp2/10-Agl4 and S 194/5. XXO. BUT.1. In atypical fusion procedure, spleen lymphocytes from an animal immunized against a chosen antigen are fused with myeloma cells. The resulting hybridomas are then dispersed in a series of separate culture tubes or microtiter plate wells to screen for cultures producing a desired antibody. Positive cultures are further diluted to obtain colonies arising from a single cell (clones). The clones are again screened for production of the desired antibody. Hybridoma cells used to make monoclonal antibodies may be grown in vitro or in the body cavity of an animal. Monoclonal antibodies may be isolated and purified from supernatants of cultured hybridoma cells or from ascites using conventional procedures such as centrifugal filtration, precipitation, chromatography or a combination thereof.

[0092] In at least some embodiments, the binding antibodies are raised against one or more proteins of SARS-CoV-2 such as the S, M, N, or E proteins of SARS-CoV-2 and are produced using recombinant DNA and protein expression technologies. Such antibodies may be made with high probability and predictability, using either of the two general methods that have been disclosed in the above-cited references, which are incorporated herein by reference.

[0093] In a general method, animals (e.g., mice) are injected with whole cells or proteins from SARS-CoV-2. Antibody producing cells from the mice are immortalized and the monoclonal antibodies produced by the immortalized cells are screened for reactivity with SARS-CoV-2, e.g., in culture. The monoclonal antibodies may then be further screened for reactivity against one or more SARS-CoV-2 proteins. In some embodiments, to identify two monoclonal antibodies that interact with different epitopes of SARS-CoV-2, the proteins can be divided into separate overlapping fragments, e.g., of 10-25 amino acid residues, and these fragments further screened for immunoreactivity to the two or more monoclonal antibodies identified as above that are immunoreactive with the different individual fragments. Alternatively, standard competitive binding studies can be employed to test pairs of monoclonal antibodies that bind to different epitopes of SARS-CoV-2.

[0094] In another general method, SARS-CoV-2 proteins or protein fragments are prepared for example, by recombinant expression of SARS-CoV-2 coding sequences. The isolated proteins or protein fragments are then used directly as an immunogen, e.g., in mice, for producing hybridoma cell lines. The monoclonal antibodies produced by the cell lines are then screened for antibodies immunoreactive against the protein. One of the methods disclosed above may then be employed to identify two or more monoclonal antibodies which are immunoreactive with different epitopes of SARS-CoV-2. [0095] FIG. 6 illustrates an example method of tracking infection so that an individual may participate in a group event. In this method, the individual visits a testing center to receive a test. The results of the test are transmitted, by a computing device such as a smartphone, to another computing system over a network. In some embodiments, the identity of the individual is not associated with the test. Instead, the test results are associated with a unique identifier of the test (e.g., which may be included with a test kit). The computing device used to transmit the test results may include a specialized reader for reading the results of the test strip. The reader may be reusable or disposable (e.g., configured for one-time use).

[0096] In some embodiments, a biometric identifier of the individual may be captured (e.g., using a biometric measurement device) and transmitted along with the test results. For example, a retinal image or scan may be captured and associated with the test. The retinal image or scan may be captured with a photograph, which may be taken using a smartphone used to transmit the test results. In some implementations, the photograph may be taken while the test is being administered and may include the individual’s retina and an identifier of the test (e.g., a QR code or code on a swab that is used to gather sample from the patient). Other biometric values may also be captured for the individual too. In some embodiments, a temperature reading from the individual is taken and transmitted along with the test results. If the temperature indicates that the individual has a temperature, the test results may be considered inconclusive and may result in denial of admission regardless of the results of the lateral flow analysis. Similarly, location information about where the test was performed (e.g., as determined by a GPS chip associated with the computing device transmitting the test results).

[0097] Temperature readings may include a numeric temperature value taken via a temporal scan, orally, or otherwise. Temperature readings may also include multiple temperature readings generated from one or more infrared images (e.g., a static image or a video). In some implementations, the temperature readings include thermal signatures obtained using image processing or artificial intelligence techniques on the one or more infrared images. The thermal signatures may be based on the temperature values and variations at multiple locations on an individual’s face, head, or body. The thermal signatures may be usable to differentiate between normal temperature variations in healthy (non-infected) individuals and temperature variation caused by SARS-CoV-2 infection.

[0098] The individual is then given a wearable identifier such as a bracelet or anklet, which may be placed on the individual by the test administrator. In some embodiments, the wearable identifier may include components (e.g., a lock) that make it difficult for the individual to remove without additional equipment. In some embodiments, the wearable identifier includes tamper resistant technology such that it will be difficult or impossible for an individual to remove the wearable identifier without damaging or altering the wearable identifier. Examples of tamper resistant technology include wristbands made from Tyvek® material or another plastic material with an adhesive region that includes die cuts. Once adhered to an individual, removing the wristband would destroy the adhesive region, making it readily apparent if a wristband has been removed or transferred to another individual.

[0099] The wearable identifier includes a unique identifier that can be used to retrieve the associated test results or a corresponding status value. The status value may correspond to the likelihood that the individual associated with the unique identifier is at a specific time a contagious carrier of SARS-CoV-2. In some embodiments, a status value of ADMIT may be provided for a specific duration of time following a negative SARS-CoV-2 test to indicate the unique identifier is associated with an individual who is unlikely be a contagious carrier of SARS-CoV-2. In contrast, a status value of DO NOT ADMIT may be provided to indicate that the unique identifier is not currently associated with test results indicating the individual is non- contagious.

[0100] For example, prior to admitting the individual to a location or event, an administrator may scan a computer readable code (e.g., a QR code, a barcode, etc.) on the wearable identifier to retrieve the status value to confirm that the individual tested negative and the test results are valid. The test results or status value may be considered valid for a predetermined time period (e.g., 24 hours).

[0101] The individual can then attend a group event (e.g., an event that would not be possible to attend with social distancing policies) for that time period following a negative test result. Similar processes may be used before or after air travel, use of mass transit, granting access to certain facilities, etc. In some implementations, the wearable identifier may include a test strip. [0102] In some implementations, the duration of validity for the status value may be based on combining multiple different types of test results or temperature readings, which is sometimes referred to as test stacking. For example, a status value for an individual who has a negative test for SARS-CoV-2 but a positive serological test for SARS-CoV-2 antibodies (e.g., indicating a previous infection with SARS-CoV-2) may have a longer duration of validity (e.g., 2 weeks) than a status value for an individual who has simply had a negative test for SARS-CoV-2 (e.g., 24 hours). This difference in duration may reflect the reduced likelihood that an individual who has SARS-CoV-2 antibodies and has presumably recovered from a SARS-CoV-2 infection will be re-infected. The length of the additional duration may be based on if and for how long SARS-CoV-2 antibodies provide complete or partial immunity to re-infection.

[0103] In some embodiments, an individual’s test results may be associated with information about the testing materials or equipment used, and the duration of validity may vary based on those materials or equipment. For example, tests performed with equipment that has a higher specificity or sensitivity may result in a status value that has a longer duration of validity. Furthermore, if information about the materials or equipment comes to light after a test has been completed, the duration of validity may be adjusted accordingly. For example, if after a test is completed, it is discovered that a specific batch of testing materials for a serological test is defective, the status values for any associated unique identifiers may be changed accordingly.

[0104] An example method for providing admission includes retrieving a test identifier from an individual. The test identifier may be received by scanning an identifier code on a wearable identifier worn by the individual. The method also includes retrieving an infection status indicator based on the test identifier. Retrieving the infection status indicator may include transmitting a request, by a computing device, over a network, to another computing device and receiving a response that includes the infection status indicator. The request may include the test identifier. The response may indicate that the test identifier is associated with a valid negative test result. The response may indicate that the test identifier is associated with a test result that is no longer valid for admission (e.g., the test results indicate a current infection, or the test result has expired due to the passage of time and the test results can no longer be relied upon to indicate that the individual is infection free). In some embodiments, the response may also indicate that the test identifier is associated with a positive test result. The method may also include admitting or denying access to the individual based on the received test result.

[0105] As previously described, ACE2 may be used in an immunoassay to detect the presence of SAR-CoV-2. ACE2 is a type I transmembrane metallocarboxypeptidase. ACE2 is expressed in various human cells, including in the lungs, kidney, gastrointestinal tract, vascular endothelial cells, renal tubular epithelium, and testes. In some implementations, ACE2 may be used to bind to the SARS-CoV-2 whole virus. For example, ACE2 may be used to bind to the whole virus in various immunoassays for infection testing and diagnostics. Other examples include using ACE2 or a portion of ACE2 to bind to the SARS-CoV-2 whole virus for diagnosis of SARS-CoV-2 infection. In these examples, the ACE2 or portion thereof may be recombinant ACE2 and may include ACE2 Fc. The Fc portion of the ACE2 may include a marker (e.g., a chromatic, magnetic, fluorescent or other type of marker) or other agent.

[0106] The use of ACE2 or portions thereof to bind to SARS-CoV-2 may provide methods for preventing or treating a SARS-CoV-2 infection in an individual or for inducing an immune response against SARS-CoV-2 in an individual. The methods may be conducted for prophylactic, ameliorative, palliative, or therapeutic purposes to induce an immune response against, prevent, or treat infection by SARS-CoV-2.

[0107] The methods of this disclosure may be used to induce an immune response against SARS-COV-2 in an individual. It will be understood that “inducing” an immune response as contemplated herein includes inciting an immune response and modulating a previously existing immune response (e.g., enhancing an existing immune response). “Enhancing” an immune response as contemplated herein refers to augmenting the immune response such as, for example, innate immunity or adaptive immunity (e.g. humoral responses) in a subject against SARS-CoV-2.

[0108] The use of ACE2 to bind to whole (intact) SARS-CoV-2 may be useful in immunoassays (as described elsewhere herein) and in vivo to decrease viremia. As another example, ACE2 may be used for the detection of SARS-CoV-2 when used in bio-sensors to detect and quantify SARS-CoV-2 for diagnostic purposes or to detect and quantify SARS-CoV-2 in the course of attenuated vaccine production.

[0109] Pharmaceutical compositions of ACE2 for the methods disclosed herein may be in a form suitable for administration by injection, in a formulation suitable for oral ingestion (such as, for example, capsules, tablets, caplets, elixirs), in the form of an ointment, cream, or lotion suitable for topical administration, in a form suitable for delivery as an eye drop, in an aerosol form suitable for administration by inhalation, such as by intranasal inhalation or oral inhalation, or in a form suitable for parenteral administration, that is, subcutaneous, intramuscular or intravenous injection.

[0110] FIG. 7 illustrates an example architecture of a computing device 950 which can be used to implement aspects of the present disclosure, including any of the plurality of computing devices described herein, such as a computing device for uploading test results, retrieving test results, and deciphering test strip results in some embodiments, or any other computing devices that may be utilized in the various possible embodiments.

[0111] The computing device illustrated in FIG. 7 can be used to execute the operating system, application programs, and software modules described herein.

[0112] The computing device 950 includes, in some embodiments, at least one processing device 960, such as a central processing unit (CPU). A variety of processing devices are available from a variety of manufacturers, for example, Intel or Advanced Micro Devices. In this example, the computing device 950 also includes a system memory 962, and a system bus 964 that couples various system components including the system memory 962 to the processing device 960. The system bus 964 is one of any number of types of bus structures including a memory bus, or memory controller; a peripheral bus; and a local bus using any of a variety of bus architectures. [0113] Examples of computing devices suitable for the computing device 950 include a desktop computer, a laptop computer, a tablet computer, a mobile computing device (such as a smartphone, an iPod® or iPad® mobile digital device, or other mobile devices), or other devices configured to process digital instructions.

[0114] The system memory 962 includes read only memory 966 and random-access memory 968. A basic input/output system 970 containing the basic routines that act to transfer information within computing device 950, such as during start up, is typically stored in the read only memory 966.

[0115] The computing device 950 also includes a secondary storage device 972 in some embodiments, such as a hard disk drive, for storing digital data. The secondary storage device 972 is connected to the system bus 964 by a secondary storage interface 974. The secondary storage devices 972 and their associated computer readable media provide nonvolatile storage of computer readable instructions (including application programs and program modules), data structures, and other data for the computing device 950.

[0116] Although the example environment described herein employs a hard disk drive as a secondary storage device, other types of computer readable storage media are used in other embodiments. Examples of these other types of computer readable storage media include magnetic cassehes, flash memory cards, digital video disks, Bernoulli cartridges, compact disc read only memories, digital versatile disk read only memories, random access memories, or read only memories. Some embodiments include non-transitory computer-readable media. Additionally, such computer readable storage media can include local storage or cloud-based storage.

[0117] A number of program modules can be stored in secondary storage device 972 or system memory 962, including an operating system 976, one or more application programs 978, other program modules 980 (such as the software engines described herein), and program data 982. The computing device 950 can utilize any suitable operating system, such as Microsoft Windows™, Google Chrome™ OS or Android, Apple OS, Unix, or Linux and variants and any other operating system suitable for a computing device. Other examples can include Microsoft, Google, or Apple operating systems, or any other suitable operating system used in tablet computing devices. [0118] In some embodiments, a user provides inputs to the computing device 950 through one or more input devices 984. Examples of input devices 984 include a keyboard 986, mouse 988, microphone 990, and touch sensor 992 (such as a touchpad or touch sensitive display). Other embodiments include other input devices 984. The input devices are often connected to the processing device 960 through an input/output interface 994 that is coupled to the system bus 964. These input devices 984 can be connected by any number of input/output interfaces, such as a parallel port, serial port, game port, or a universal serial bus. Wireless communication between input devices and the interface 994 is possible as well, and includes infrared, BLUETOOTH® wireless technology, 802.11a/b/g/n, cellular, ultra-wideband (UWB), ZigBee, or other radio frequency communication systems in some possible embodiments.

[0119] In this example embodiment, a display device 996, such as a monitor, liquid crystal display device, projector, or touch sensitive display device, is also connected to the system bus 964 via an interface, such as a video adapter 998. In addition to the display device 996, the computing device 950 can include various other peripheral devices (not shown), such as speakers or a printer.

[0120] When used in a local area networking environment or a wide area networking environment (such as the Internet), the computing device 950 is typically connected to the network through a network interface 1000, such as an Ethernet interface or WiFi interface. Other possible embodiments use other communication devices. For example, some embodiments of the computing device 950 include a modem for communicating across the network.

[0121] The computing device 950 typically includes at least some form of computer readable media. Computer readable media includes any available media that can be accessed by the computing device 950. By way of example, computer readable media include computer readable storage media and computer readable communication media.

[0122] Computer readable storage media includes volatile and nonvolatile, removable and non-removable media implemented in any device configured to store information such as computer readable instructions, data structures, program modules or other data. Computer readable storage media includes, but is not limited to, random access memory, read only memory, electrically erasable programmable read only memory, flash memory or other memory technology, compact disc read only memory, digital versatile disks or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and that can be accessed by the computing device 950.

[0123] Computer readable communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” refers to a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, computer readable communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, radio frequency, infrared, and other wireless media. Combinations of any of the above are also included within the scope of computer readable media.

[0124] The computing device illustrated in FIG. 7 is also an example of programmable electronics, which may include one or more such computing devices, and when multiple computing devices are included, such computing devices can be coupled together with a suitable data communication network so as to collectively perform the various functions, methods, or operations disclosed herein.

[0125] The various embodiments described above are provided by way of illustration only and should not be construed to limit the claims attached hereto. Those skilled in the art will readily recognize various modifications and changes that may be made without following the example embodiments and applications illustrated and described herein, and without departing from the true spirit and scope of the following claims.

[0126] Some non-limiting examples are provided below:

[0127] Example 1: A lateral flow assay test strip for detecting SARS-CoV-2 in a sample, the test strip comprising: an elongated porous matrix having an upstream end and a downstream end; a receiving region disposed proximal to the upstream end for receiving the sample; a reaction region downstream of the receiving region, the reaction region including a mobile, labeled binding agent that is capable of binding to SARS-CoV-2 to form a mobile, labeled virus complex; and a detection region formed on the matrix downstream of the reaction region, the detection region including a capture reagent fixedly deposited in the matrix, the capture reagent being selected to specifically bind to mobile, labeled virus complexes formed in the reaction region. [0128] Example 2: The lateral flow assay of claim 1, wherein the labeled binding agent is selected to specifically bind to SARS-CoV-2.

[0129] Example 3: The lateral flow assay of any one of claims 1 or 2, wherein the labeled binding agent includes monoclonal antibodies that are capable of binding to SARS-CoV-2.

[0130] Example 4: The lateral flow assay of claim 3, wherein the monoclonal antibodies are selected to specifically bind to SARS-CoV-2.

[0131] Example 5: The lateral flow assay of any one of claims 1-4, wherein the labeled binding agent includes polyclonal antibodies that are capable of binding to SARS-CoV-2. [0132] Example 6: The lateral flow assay of claim 5, wherein the polyclonal antibodies are selected to specifically bind to SARS-CoV-2.

[0133] Example 7: The lateral flow assay of any one of claims 1-6, wherein the labeled binding agent includes mixed monoclonal antibodies that are capable of binding to SARS-CoV-2.

[0134] Example 8: The lateral flow assay of claim 7, wherein the mixed monoclonal antibodies are selected to specifically bind to SARS-CoV-2.

[0135] Example 9: The lateral flow assay of any one of claims 7 or 8, wherein the labeled binding agent includes at least two different monoclonal antibodies that are capable of binding to SARS-CoV-2.

[0136] Example 10: The lateral flow assay of any one of claims 7-9, wherein the mixed monoclonal antibodies include monoclonal antibodies selected from at least two of the following groups: monoclonal antibodies selected to specifically bind to an S protein of SARS-CoV-2; monoclonal antibodies selected to specifically bind to an M protein of SARS-CoV-2; monoclonal antibodies selected to specifically bind to an E protein of SARS-CoV-2; monoclonal antibodies selected to specifically bind to the N protein of SARS-CoV-2; and monoclonal antibodies selected to specifically bind to sugars expressed by SARS-CoV-2.

[0137] Example 11: The lateral flow assay of any one of claims 7-10, wherein the mixed monoclonal antibodies include a defmed-ratio mixed monoclonal antibodies, wherein the defmed-ratio mixed monoclonal antibodies includes at least two different monoclonal antibodies in a specified ratio.

[0138] Example 12: The lateral flow assay of claim 11, wherein the specified ratio is selected based on evaluating various ratios to identify a ratio that results in increased binding to the SARS-CoV-2 in test samples.

[0139] Example 13: The lateral flow assay of claim 12, wherein the specified ratio is selected based on testing to identify a ratio that increases one or more of sensitivity and specificity.

[0140] Example 14: The lateral flow assay of any one of claims 1-13, wherein the labeled binding agent includes antibodies derived using whole SARS-CoV-2 virus. [0141] Example 15: The lateral flow assay of claim 14, wherein the labeled binding agent includes antibodies derived using whole SARS-CoV-2 virus captured from an infected individual. [0142] Example 16: The lateral flow assay of any one of claims 1-15, wherein the labeled binding agent includes ACE2 proteins or portions of ACE2 protein that includes the receptor to which an S protein of SARS-CoV-2 binds.

[0143] Example 17: The lateral flow assay of any one of claims 1-16, further comprising an alternate detection region formed on the matrix downstream of the reaction region, the alternate detection region including an alternate capture reagent fixedly deposited in the matrix.

[0144] Example 18: The lateral flow assay of claim 17, wherein the alternate capture reagent is selected to specifically bind to the mobile, labeled virus complex formed in the reaction region.

[0145] Example 19: The lateral flow assay of claim 17, wherein the reaction region includes an alternate mobile, labeled binding agent that is capable of binding to SARS-CoV-2 to form an alternate mobile, labeled virus complex and the alternate capture reagent is selected to specifically bind to the alternate mobile, labeled virus complex formed in the reaction region.

[0146] Example 20: The lateral flow assay of claim 19, wherein the alternate mobile, labeled binding agent includes one or more of the following: the monoclonal antibodies are selected to specifically bind to SARS-CoV-2; polyclonal antibodies are selected to specifically bind to SARS-CoV-2; mixed monoclonal antibodies are selected to specifically bind to SARS-CoV-2; and ACE2 proteins or portions of ACE2 protein that includes the receptor to which an S protein of SARS-CoV-2 binds.

[0147] Example 21: The lateral flow assay of any one of claims 1-20, further comprising a control region disposed downstream of the detection region, wherein the reaction region further includes mobile, labeled control agents and the control region includes a control reagent fixedly deposited in the matrix, the control reagent being selected to specifically bind to the mobile, labeled control agents.

[0148] Example 22: The lateral flow assay of claim 21, wherein the detection region includes a rectangular strip of capture reagent fixedly deposited in the matrix and the control region includes a rectangular strip of control reagent fixedly deposited in the matrix.

[0149] Example 23: The lateral flow assay of claim 21, wherein the detection region includes a non-rectangular shaped region of capture reagent fixedly deposited in the matrix and the control region includes a non-rectangular shaped region of control reagent fixedly deposited in the matrix.

[0150] Example 24: The lateral flow assay of claim 23, wherein the detection region includes an irregular shaped region of capture reagent fixedly deposited in the matrix and the control region includes an irregular shaped region of control reagent fixedly deposited in the matrix.

[0151] Example 25: The lateral flow assay of any one of claim 23 or 24, wherein the detection region and the control region are arranged to provide an encoded result. [0152] Example 26: The lateral flow assay of any one of claims 23-25, wherein the detection region and the control region are arranged such that an infection status of an individual is not apparent from viewing the detection region and control region.

[0153] Example 27: The lateral flow assay of any one of claims 23-26, including a key that is usable to decipher an infection status of an individual.

[0154] Example 28: The lateral flow assay of any one of claims 1-27, further comprising an integrity control region disposed downstream of the detection region, wherein the reaction region further includes a mobile, labeled integrity control binding agent that is capable of binding to protein expected to be present in a sample from an individual to form a mobile, labeled integrity control complex, the integrity control region including an integrity control reagent fixedly deposited in the matrix, the integrity control reagent being capable of binding to the mobile, labeled integrity control complex.

[0155] Example 29: The lateral flow assay of claim 28, wherein the labeled integrity control binding agent includes integrity control antibodies that are selected to specifically bind to protein that is expected to be present in a sample from an individual.

[0156] Example 30: The lateral flow assay of any one of claims 1-29, wherein the porous matrix is configured to allow a capillary fluid flow from the upstream end to the downstream end.

[0157] Example 31: The lateral flow assay of any one of claims 1-30, further comprising a reservoir pad disposed proximal to the downstream end of the porous matrix. [0158] Example 32: The lateral flow assay of any one of claims 1-31, further comprising a porous-material pad that includes that sample receiving region and is disposed on the matrix proximal to the upstream end.

[0159] Example 33: The lateral flow assay of any one of claims 1-32, wherein the mobile, labeled binding agent includes at least one of visible labels and fluorescent labels.

[0160] Example 34: A system comprising: the lateral flow assay of any one of claims 1-33; and a reader device for reading the results of the lateral flow assay.

[0161] Example 35: The system of claim 34, wherein the reader includes a computing device.

[0162] Example 36: The system of claim 35, wherein the computing device includes at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the computing device to perform a method including: capturing an image of the detection region of the lateral flow assay; and determining an infection status based on the image of the detection region.

[0163] Example 37: The system of claim 36, wherein the determining the infection status based on the image of the infection region includes transmitting the image to a server computing device and receiving infection status data from the server computing device.

[0164] Example 38: The system of claim 37, wherein the determining the infection status based on the image of the infection region includes transmitting a key associated with the lateral flow assay to the server computing device.

[0165] Example 39: The system of claim 38, wherein the method further includes capturing an image of the key.

[0166] Example 40: The system of any one of claims 34-39, wherein the computing device includes a smartphone.

[0167] Example 41: The system of claim 34, wherein the reader device is a disposable reader device that is configured for one-time use.

[0168] Example 42: The system of claim 34, further comprising a biometric measurement device to capture a biometric identifier of the patient.

[0169] Example 43: A method comprising: capturing an image of a detection region of a lateral flow assay; receiving a key associated with the lateral flow assay; and determining an infection status based on the image of the detection region and the key.

[0170] Example 44: A computing device comprising: at least one processor; and memory storing instructions that, when executed by the at least one processor, cause the computing device to perform the method of claim 43.

[0171] Example 45: Anon-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, cause a computing system to perform the method of claim 43.

[0172] Example 46: A method for detecting the presence of SARS-CoV-2 infection, the method comprising: collecting a sample from an individual; applying the sample to the receiving region of the lateral flow assay of any one of claims 1-41; detecting whether the labeled binding agent is present in the detection region of the lateral flow assay; and determining an infection status of the individual based on whether the labeled binding agent is detected in the detection region.

[0173] Example 47: The method of claim 46, wherein the collecting the sample from the individual includes collecting a nasopharyngeal sample or a saliva sample.

[0174] Example 48: The method of any one of claims 46 or 47, wherein the detecting whether the labeled binding agent is present includes visually inspecting the detection region.

[0175] Example 49: The method of any one of claims 46 or 47, wherein the detecting whether the labeled binding agent is present includes inspecting the detection region with a specialized reader.

[0176] Example 50: A method for detecting the presence of SARS-CoV-2 infection, the method comprising: collecting a sample from an individual; applying the sample to a receiving region of a lateral flow assay, wherein the lateral flow assay includes a reaction region that includes mobile, labeled binding agents that specifically bind to SARS-CoV-2 and a detection region that includes fixed binding agents that specifically bind to SARS-CoV-2; and detecting whether the labeled binding agents are present in the detection region of the test strip.

[0177] Example 51: The method of claim 50, wherein the mobile, labeled binding agents include include one or more of human ACE2 protein, a portion of the ACE2 protein that includes the receptor that the SARS-CoV-2 spike protein binds to, monoclonal antibodies that specifically bind to SARS-CoV-2, polyclonal antibodies that specifically bind to SARS-CoV-2, and mixed monoclonal antibodies that specifically bind to SARS-CoV-2.

[0178] Example 52: The method of any one of claims 50 or 51, wherein the fixed binding agents include one or more of human ACE2 protein, a portion of the ACE2 protein that includes the receptor that the SARS-CoV-2 spike protein binds to, monoclonal antibodies that specifically bind to SARS-CoV-2, polyclonal antibodies that specifically bind to SARS-CoV-2, and mixed monoclonal antibodies that specifically bind to SARS-CoV-2.

[0179] Example 53: The method of any one of claims 50-52, wherein the collecting the sample from the individual includes collecting a nasopharyngeal sample or a saliva sample.

[0180] Example 54: The method of any one of claims 50-53, wherein the detecting whether the labeled binding agent is present includes visually inspecting the detection region.

[0181] Example 55: The method of any one of claims 50-53, wherein the detecting whether the labeled binding agent is present includes inspecting the detection region with a specialized reader.