ASSAYS TO DETECT COMPOUNDS THAT BIND THE SARS-COV-2 SPIKE PROTEIN CROSS-REFERENCE TO RELATED APPLICATION [0001] This application claims priority to US Provisional Patent Application No. 63/027,778 filed May 20, 2020 the entire contents of which are incorporated by reference herein in their entirety. FIELD OF THE DISCLOSURE [0002] The current disclosure provides microparticle-based in vitro assays that detect antibodies that bind the SARS-CoV-2 spike protein and that detect binding between the SARS-CoV-2 spike protein and human angiotensin-converting enzyme 2 (hACE2). The assays can quantify inhibition of such binding by either human serum/plasma or drug candidates. The assay is compatible with high-throughput screening systems. BACKGROUND OF THE DISCLOSURE [0003] In late 2019 the novel severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) emerged in Wuhan, China. It rapidly spread across the globe, and the disease it causes, COVID19, was declared a pandemic by the World Health Organization (WHO) in March 2020. The SARS-CoV-2 spike glycoprotein is its viral surface protein that mediates host (e.g., human) cell entry. This spike protein has a trimeric structure with either none or one of three receptor binding domains (RBDs) in the “up” state, capable of binding to its target. Similar to the 2003 SARS virus, the SARS-CoV-2 spike glycoprotein’s target protein on host cells is angiotensin converting enzyme 2 (ACE2). Binding of the SARS-CoV-2 spike protein to ACE2 is necessary and sufficient for infection of the target cell. While knowledge regarding SARS-CoV-2 is expanding rapidly, a need to identify compounds that inhibit binding between the SARS-CoV-2 spike protein and ACE2 is needed. Such compounds could provide valuable prophylactic and/or therapeutic treatments against COVID19. SUMMARY OF THE DISCLOSURE [0004] The current disclosure provides microparticle-based vitro assays that detect antibodies that bind the SARS-CoV-2 spike protein and that detect binding between the SARS-CoV-2 spike protein and ACE2. The disclosed assays can detect compounds that interfere with SARS-CoV-2 spike protein and ACE2 binding and can quantify the degree of interference. The assays can be used for many purposes including, for example, assessing functional immunity in recovered patients, screening plasma donations for potency in the context of convalescent plasma therapy, screening drug libraries for compounds that inhibit binding of SARS-CoV-2 to ACE2, and assessing mutant spike proteins to test existing immunity against potentially emerging viral strains. When used to screen drug libraries that do not include serum/plasma, the assay does not require biosafety containment (i.e., can be safely run at biosafety level 0) and can be practiced in a high throughput manner. BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS [0005] Some of the drawings submitted herein may be better understood in color. Applicant considers the color versions of the drawings as part of the original submission and reserves the right to present color images of the drawings in later proceedings. [0006] FIGs. 1A-1D. Graphical depictions of particle-based assays. (1A) Ig-detection based assay. 5 µm immunoprecipitation detected by flow cytometry (IP-FCM) beads are coated with COVID-spike protein (triangles). Beads are then incubated with human serum, and antibodies within the serum (IgG) bind the spike protein. Phycoerythrin (PE)-labeled anti-human-IgG or -IgM antigen binding fragment (FAB) fragments are used to detect human antibodies binding the spike protein. (1B) Hypothetical data. A low baseline fluorescence value of the bead population shifts to a higher value in the presence of immune sera. (1C) For this depicted binding assay, human ACE2 (hACE2) is coupled to 5 µm IP-FCM beads. Beads are then incubated with biotinylated spike protein with or without potential inhibitors and probed with streptavidin-PE to detect spike protein. (1D) In the presence of an effective binding inhibitor, PE-fluorescence is reduced. [0007] FIG.2. Binding (“No Serum”) of an ACE2-COV2 trimer and inhibition of binding by serum from COVID+ patients (left column). [0008] FIGs. 3A-3E. Detection of anti-SARS-CoV-2 IgG in serum from recovered COVID19 patients. (3A) Plasma from 3 COVID+ samples and two controls was serially diluted, and IgG levels were measured using the Trimer-conjugated beads. (3B) Plasma from 3 COVID+ samples and two controls was serially diluted, and IgG levels were measured using the RBD-conjugated beads. (3C) Plasma from 14 COVID+ and 6 pre-covid controls was diluted 1:1000, and IgG levels were measured using the Trimer-conjugated beads. (3D) Plasma from 14 COVID+ and 6 pre- covid controls was diluted 1:1000, and IgG levels were measured using the RBD-conjugated beads. (3E) The median fluorescent intensity of IgG measured on the trimer and RBD assays was significantly correlated. [0009] FIGs. 4A-4E. Development of an in vitro Trimer-Spike binding assay. (4A) ACE2- conjugated CML beads were mixed with increasing dilutions of biotinylated Trimer (left) or RBD (right) and detected with streptavidin-PE ( histograms). Soluable, unlabeled ACE2 was added to inhibit binding to establish specificity ( histograms), which inhibited binding by >90%. BSA- conjugated CML beads ( histograms) and no-biotinylated-spike controls ( histograms) were included as negative controls. (4B) The EC50 of the ACE2-Trimer binding reaction was determined by serial dilution of the trimer. (4C) The EC50 of the ACE2-RBD binding reaction was determined by serial dilution of the RBD. (4D) Serial dilution of COVID+ and pre-COVID control plasma was performed to determine the optimal dilution of plasma samples. (4E) Serial dilution of COVID+ “RBD responders” and pre-COVID control plasma was performed to determine the optimal dilution of plasma samples. [0010] FIGs.5A-5E. COVID+ plasma samples inhibit Ace2-Spike interaction. (5A) Compared to a no-serum control ( ), pre-COVID control serum significantly inhibited Trimer-ACE2 binding (p<0.05), but COVID+ serum inhibited binding to a much greater degree (P<0.001 vs control serum and no serum). (5B) Same data as in 5A expressed as % inhibition vs the no-serum control average. An arbitrary cut-off of 85% inhibition captures all IgG-positive COVID samples. P<0.001. (5C) Compared to a no-serum control ( ), pre-COVID control serum slightly and non-significantly inhibited RBD-ACE2 binding. COVID+ serum inhibited in some samples, such that the group mean was significantly different from both pre-COVID and no serum controls (P<0.005 vs control serum and p<0.01 vs no serum). However, the population appeared to bifurcate into a responder and non-responder population (dotted line at MFI = 20,000). (5D) Same data as in 5C expressed as % inhibition vs the no-serum control average. P<0.005. (5E) If the COVID+ population is split by the dashed lines in 5C and 5D, the non-responder population is not significantly different from pre-COVID or no serum controls, while the responder population is (P<0.001). [0011] FIGs.6A, 6B. Depletion of serum with trimer-conjugated beads prevents inhibition of Ace2 binding. (6A) Trimer-ACE2 inhibition from undepleted serum or serum depleted with BSA-coated beads is not significantly different. However, after depletion with three rounds of trimer-conjugated CML beads, all three samples were no longer able to inhibit ACE2-Trimer binding. P<0.05 vs BSA-depleted serum (6B) RBD-ACE2 inhibition from undepleted serum or serum depleted with BSA-coated beads is not significantly different. However, after depletion with three rounds of trimer-conjugated CML beads, both responders showed significantly reduced inhibition (p<0.05), while the non-responder and the pre-COVID control were not significantly different from BSA- depleted serum. [0012] FIGs.7A-7C. Trimer IgG levels correlate with inhibition, while RBD IgG levels do not. (7A) Trimer MFI plotted against % inhibition on the Trimer-ACE2 inhibition assay for all COVID+ samples. (7B) RBD MFI plotted against % inhibition on the RBD-ACE2 inhibition assay for all COVID+ samples. (7C) % inhibition on the Trimer-ACE2 inhibition assay plotted against % inhibition on the RBD-ACE2 inhibition assay. DETAILED DESCRIPTION [0013] Microparticle-based in vitro assays to detect antibodies that bind the SARS-CoV-2 spike protein and detect binding of SARS-CoV-2 spike protein to ACE2 are described. In particular embodiments, the assay is based on Immunoprecipitation detected by flow cytometry (IP-FCM) technology, a highly sensitive and reagent efficient method for detecting protein-protein interactions. IP-FCM is based on the principles of sandwich enzyme-linked immunosorbent assays (ELISA). In brief, the method involves coupling of microparticles with a capture protein that specifically binds a protein of interest (also referred to as a captured protein or target molecule). These protein-coated microparticles are incubated with a solution that may contain the protein of interest. The solution that may contain the protein of interest can include additional substances that may or may not inhibit the binding of the target molecule to the protein-coated microparticle. Following incubation, captured protein complexes can be analyzed with detectable probes and microparticle-associated fluorescence by flow cytometry. IP-FCM shows high sensitivity to small changes in physiologic protein-protein interactions. [0014] In particular embodiments, microparticle-based assays disclosed herein include a plurality of microparticles coated with a capture protein, wherein the capture protein is a form of the SARS- CoV-2 spike protein or ACE2. When the capture protein is a form of the SARS-CoV-2 spike protein, the protein of interest (capture protein or target molecule) an antibody that binds the SARS-CoV-2 spike protein or ACE2. When the capture protein is ACE2, the protein of interest (capture protein or target molecule) is a form of the SARS-CoV-2 spike. [0015] In certain examples, the capture protein-conjugated microparticles are incubated with a sample that can include the target molecule and a detection molecule that specifically binds to the target molecule. The detection molecule is labeled with a detectable label. If the sample contained the target molecule and the capture protein was able to bind the target molecule, a sandwiched configuration is formed in which the capture protein-conjugated microparticle is bound to the target molecule which is also bound to a detection molecule, such as a fluorophore labeled-antibody. For a depiction of this type of assay, see FIG.1A. This type of assay is useful to rapidly screen serum or plasma samples for neutralizing antibodies that block the interaction between the SARS-CoV-2 spike protein and ACE2. [0016] In particular embodiments, microparticle-based assays include a plurality of microparticles coated with a capture protein that specifically binds to a target molecule. The capture protein- conjugated microparticles are incubated with a labeled target molecule. Additional substances may be added to the reaction that may or may not inhibit the binding of the labeled target molecule to the capture protein-coated microparticle. A sandwiched configuration is formed in which the capture protein-conjugated microparticle is bound to the labeled target molecule which is also bound by a detectable label. This configuration may or may not be prevented from forming by the additional substances added. For a depiction of this type of assay, see FIG. 1C. To detect compounds that interfere with binding, a sample containing a potential binding inhibitor can be included in the mixture with the capture protein-conjugated microparticles, and the labeled target molecule. A decrease in observed binding based on the presence of the sample containing the potential binding inhibitor indicates the presence of an actual binding inhibitor (e.g., effective antibody, protein, peptide, nucleic acid, or small molecule drug). Other protein, peptide, nucleic acid, and/or small molecule drug libraries can also be screened. [0017] In particular embodiments, the capture protein-conjugated microparticles, samples, labeled target molecules, and/or detection molecules (e.g., antibody, tag binder-detectable label conjugate (e.g., streptavidin-PE)), can be mixed and incubated at the same time or sequentially. In particular embodiments, the capture protein-conjugated microparticles and the sample can be mixed and incubated first. Mixtures are incubated for time sufficient to allow cognate binding. Afterwards, the mixture can be analyzed by flow cytometry to examine the amount of target molecule attached to each microparticle. [0018] Microparticles refer to small discrete particles including microbeads, nanobeads, nanoshells, or nanodots. Microparticles can include, for example, latex beads, polystyrene beads, fluorescent beads, and/or colored beads, and can be made from organic matter and/or inorganic matter. They can be made of any suitable materials that allow for the conjugation of capture proteins to their surface. Examples of suitable materials include: ceramics, glass, polymers, and magnetic materials. Suitable polymers include polystyrene, poly-(methyl methacrylate), poly- (lactic acid), (poly-(lactic-co -glycolic acid)), polyesters, polyethers, polyolefϊns, polyalkylene oxides, polyamides, polyurethanes, polysaccharides, celluloses, polyisoprenes, methylstyrene, acrylic polymers, thoria sol, latex, nylon, Teflon cross- linked dextrans (e.g., Sepharose), chitosan, agarose, and cross-linked micelles. Additional examples include carbon graphited, titanium dioxide, and paramagnetic materials. See, e.g., "Microsphere Detection Guide" from Bangs Laboratories, Fishers Ind. In particular embodiments, microparticles can be made of one or more materials. In particular embodiments, microparticles are paramagnetic microparticles. Particular embodiments utilize carboxy-modified polystyrene latex (CML) flow cytometry beads and/or magnetic MagPlex® (Luminex, Austin, TX) flow cytometry beads. [0019] In particular embodiments, microparticles used within an assay are homogeneous in size and absorbing ability. In particular embodiments, the microparticles are solid and insoluble in a sample of interest to facilitate separation from the sample. In particular embodiments the microparticle material is inert to components in the sample and the reagent. [0020] In particular embodiments, the microparticle can range in size from having a radius or diameter of from, for example, 20 nm to 1000 μm, 200 nm to 200 μm, or 1.0 μm to 10 μm. [0021] In particular embodiments, the capture protein is conjugated to the surface of the microparticle by any method known in the art. In particular embodiments, the capture protein is conjugated to the surface of the microparticle according to the chemistry of the microparticle’s surface. The capture protein can be conjugated to the surface of the microparticle using adsorption or covalent attachment. In particular embodiments, the capture protein is covalently attached to the surface of the microparticle using amine-reactive coupling, sulfhydryl-reactive coupling, carbonyl-reactive coupling, active hydrogen immobilization, and/or the Mannich reaction. Amine-reactive coupling includes NHS-ester reactive groups formed by EDC, reductive amination (aldehyde coupling), azlactone ring reactivity, and carbonyl diimidazole (CDI) to activate hydroxyls. Sulfhydryl-reactive coupling includes maleimide-activated supports, iodoacetyl-activated supports, and pyridyl disulfide supports. Carbonyl-reactive coupling includes hydrazide-activated supports, carboxyl-reactive supports, and carbodiimide (EDC)-mediated crosslinking. [0022] In one example, beads (e.g., 50 μL of CML beads (Invitrogen #C37255, USA) or 250ul of MagPlex Microspheres (Luminex #MC100XX-01, USA)) can be washed with room temperature MES and activated with EDAC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl; Pierce, USA), freshly dissolved in MES from powder stored. The beads can then be washed with PBS. After, for example, a third wash, the activated bead pellet can be resuspended in a solution containing a capture protein (e.g., 25 μg of the receptor binding domain (RBD) fragment, Trimer or ACE2 protein in PBS) and gently mixed. Coupled beads can then be washed (e.g., in PBS) and stored for later use. [0023] As indicated, capture proteins within assays disclosed herein can include ACE2 and/or a SARS-CoV-2 spike protein. Particular embodiments utilize a full-length trimeric form of the spike protein. The reference sequence can be the sequence derived from the first virus isolate, Wuhan- Hu-1, released on January 10, 2020 (Wu et al., A new coronavirus associated with human respiratory disease in China. Nature (2020). See also GenBank: MN908947.3. Additional embodiments can utilize a modified and/or stabilized version of the full-length spike protein. Stabilizing mutations can include K986P and V987P according to wild type numbering. In certain examples, at amino acid P1213, the sequence can be fused to a thrombin cleavage site, a T4 foldon sequence for proper trimerization can be utilized, and a C-terminal histidine tag can be used for purification. See, e.g., Amanat et al., doi.org/10.1101/2020.03.17.20037713; Wrapp et al., Cryo-EM structure of the 2019-nCoV spike in the prefusion conformation. Science (2020); Pallesen et al., Proc Natl Acad Sci USA 114, E7348-E7357 (2017). Polybasic cleavage sites recognized by furin can be removed. Particular embodiments can utilize a truncated RBD domain. For example, the natural N-terminal signal peptide of the spike protein can be fused to the RBD sequence (e.g., amino acid residues 319-541 according to wild type numbering) and joined with a C-terminal histidine tag. Amanat et al., doi.org/10.1101/2020.03.17.20037713; Li et al., Science, 309, 1864-1868 (2005). Particular embodiments can utilize alanine scanning or deep mutational scanning (DMS) variants of the spike protein. SARS-CoV-2 coding sequences can be codon- optimized for expression in mammalian expression systems. [0024] In certain examples, DMS variants include a complete set of possible protein variants, with 19 possible amino acid substitutions at each amino acid position. In particular embodiments, DMS variants include all possible amino acids at less than all positions of a protein, for example at 50%, 60%, 70%, 80%, 90%, 95%, 96%, 97%, 98% or 99% of positions. DMS libraries can be synthetically constructed by and/or obtained from a synthetic DNA company such as Twist Bioscience (San Francisco, CA). In particular embodiments, methods to generate a codon-DMS library include: polymerase chain reaction (PCR) mutagenesis (Dingens et al. Cell Host and Microbe. 2017;21(6):777-787; Dingens et al. Immunity. 2019 Jan 29); nicking mutagenesis as described in Wrenbeck et al. (Nature Methods 13: 928-930, 2016) and Wrenbeck et al. (Protocol Exchange doi:10.1038/protex.2016.061, 2016); PFunkel (Firnberg & Ostermeier, PLoS ONE 7(12): e52031, 2012); massively parallel single-amino-acid mutagenesis using microarray- programmed oligonucleotides (Kitzman et al., Nature Methods 12: 203-206, 2015); and saturation editing of genomic regions with CRISPR-Cas9 (Findlay et al., Nature 513(7516): 120- 123, 2014). Mutagenesis methods that give a larger proportion of single amino acid mutants are known in the art (see, e.g., Kitzman, et al., Nature Methods 12: 203–206, 2015; Firnberg & Ostermeier, PLoS One 7: e52031, 2012; Jain & Varadarajan, Anal. Biochem.449: 90–98, 2014; and Wrenbeck et al., Nature Methods 13: 928, 2016). [0025] Various test samples can be used to test for compounds that inhibit binding between the SARS-CoV-2 spike protein and hACE2. In particular embodiments, the test samples include human serum or plasma. Human serum or plasma samples can be heat-inactivated (e.g., for 30 min. at 60ºC or 1 hour for 56ºC). In certain examples, human heat-treated plasma can be centrifuged and collected supernatant plasma can be diluted. [0026] In particular embodiments, conjugate binding interactions are used for detection of binding. Conjugate binding interactions include at least two elements with high affinity and fidelity molecular recognition to each other such as in protein/ligand, antigen/antibody, sugar/lectin, and RNA/ribosome interactions. A particularly useful example of such an interaction pair is the biotin- avidin (or streptavidin) system. In particular embodiments, conjugate binding pairs include a tag and a tag binder, such as biotin and streptavidin, biotin and avidin, glutathione and glutathione S- transferase, maltose and maltose-binding protein, chitin and chitin-binding protein, fluorescein isothiocyanate (FITC) and anti-FITC, or a protein and its antibody. In particular embodiments, the tag binder is linked to a detectable label. Detectable labels can include any suitable label or detectable group detectable by, for example, optical, spectroscopic, photochemical, biochemical, immunochemical, electrical, optical or chemical means. Such detectable labels include fluorochrome, fluorescent protein, a chromophore, an enzyme, a linker molecule, a biotin molecule, an electron donor, an electron acceptor, a dye, a metal, or a radionuclide.   [0027] In particular embodiments, the tag includes biotin. In particular embodiments, the tag binder includes streptavidin. In particular embodiments, the streptavidin is linked to phycoerythrin (PE) to form the tag binder-detectable label conjugate, streptavidin-PE. [0028] Other exemplary tags include His tag, Flag tags, Xpress tag, Avi tag, Calmodulin binding peptide (CBP) tag, Polyglutamate tag, HA tags, Myc tag, Strep tag (which refers to the original STREP ^® tag, STREP ^® tag II (IBA Institut fur Bioanalytik, Germany); see, e.g., US 7,981,632), Softag 1, Softag 3, and V5. Associated tag binders are commercially available. For example, His tag antibodies are commercially available from suppliers including Life Technologies, Pierce Antibodies, and GenScript. Flag tag antibodies are commercially available from suppliers including Pierce Antibodies, GenScript, and Sigma-Aldrich. Xpress tag antibodies are commercially available from suppliers including Pierce Antibodies, Life Technologies, and GenScript. Avi tag antibodies are commercially available from suppliers including Pierce Antibodies, IsBio, and Genecopoeia. Calmodulin tag antibodies are commercially available from suppliers including Santa Cruz Biotechnology, Abcam, and Pierce Antibodies. HA tag antibodies are commercially available from suppliers including Pierce Antibodies, Cell Signal, and Abcam. Myc tag antibodies are commercially available from suppliers including Santa Cruz Biotechnology, Abcam, and Cell Signal. Strep tag antibodies are commercially available from suppliers including Abcam, Iba, and Qiagen. [0029] In particular embodiments, a detection antibody or other detection molecule, ACE2, or a SARS-CoV-2 spike protein (RBD or Trimer) is conjugated to a detectable label. [0030] In particular embodiments, the detectable label includes a fluorochrome. Any art- recognized fluorochrome can be used. Examples include R-phycoerythrin (PE), rhodamine (RDl), fluorescecin isothicyanate (FITC), cyanin 5, cyanin 7, coerythrin-cyanine 5 (PC5), allophycocyanin (APC), AlexaFluor® (Molecular Probes, Inc., Eugene, OR), carboxyfluorescein diacetate (CFSE), propidium iodide (PI), and peridinin chlorphyll protein complex (PerCP). [0031] In particular embodiments, the detectable label includes a fluorescent protein. Exemplary fluorescent proteins include blue fluorescent proteins (e.g. eBFP, eBFP2, Azurite, mKalama1, GFPuv, Sapphire, T-sapphire); cyan fluorescent proteins (e.g. eCFP, Cerulean, CyPet, AmCyanl, Midoriishi-Cyan, mTurquoise); green fluorescent proteins (e.g. GFP, GFP-2, tagGFP, turboGFP, EGFP, Emerald, Azami Green, Monomeric Azami Green (mAzamigreen)), CopGFP, AceGFP, avGFP, ZsGreenl, Oregon Green™(Thermo Fisher Scientific)); Luciferase; orange fluorescent proteins (mOrange, mKO, Kusabira-Orange, Monomeric Kusabira-Orange, mTangerine, tdTomato); red fluorescent proteins (mKate, mKate2, mPlum, DsRed monomer, mCherry, mRuby, mRFP1, DsRed-Express, DsRed2, DsRed-Monomer, HcRed-Tandem, HcRedl, AsRed2, eqFP611, mRaspberry, mStrawberry, Jred, Texas Red™ (Thermo Fisher Scientific)); far red fluorescent proteins (e.g., mPlum and mNeptune); yellow fluorescent proteins (e.g., YFP, eYFP, Citrine, SYFP2, Venus, YPet, PhiYFP, ZsYellowl); and tandem conjugates. [0032] In particular embodiments, the detectable label includes an enzyme. Exemplary enzyme labels include horseradish peroxidase, hydrolases, and alkaline phosphatase. Exemplary fluorescence labels include rhodamine, phycoerythrin, and fluorescein. [0033] In certain examples, diluted supernatant plasma can be added into wells of a plate with RBD- or Trimer-conjugated beads. The wells can be capped and the plate can be left to rotate at 4°C, for example overnight. The next day, the plate can be spun to pellet the beads and the supernatant can be discarded. In certain examples, the pelleted beads can be washed and incubated with a test sample that may include antibodies that bind the SARS-CoV-2 spike protein and a detection molecule (e.g., anti-Human IgG-PE (Jackson ImmunoResearch, #709-116-149, lot 145536, USA) or streptavidin-PE (Biolegend, # 405203)) for 30 minutes at room temperature. [0034] In particular embodiments, the sandwiched target molecule within the capture protein- conjugated microparticle and detection label can be detected by any method known in the art. In particular embodiments, the detection method includes a flow cytometer, microplate reader, Luminex reader, BeadXpress® System (Illumina, Inc., San Diego, CA) or other detection instrument. In particular embodiments, the detection method includes flow cytometry. Flow cytometry instrumentation and techniques are well-known in the art. In general, flow cytometry relies on the passage of a stream of microparticle suspension through a light beam and electro-optical sensors in such a manner that only one microparticle at a time passes through the beam-sensor region. As each microparticle passes this region, the light beam is perturbed by the microparticle, and the resulting scattered and fluorescent light are detected. The detected optical signals are used by the instrumentation to identify the subgroup to which each microparticle belongs, along with the presence and amount of label, so that individual microparticle results are achieved. [0035] For quantification of this binding, the intensity of the detectable label emitted from the detectable label on the microparticles upon irradiation of the fluorochrome with an excitation light is determined. If the intensity of the florescent emitted from the fluorochrome on one of the microparticles is above a predetermined value (i.e., a threshold or cutoff value), the test sample is determined to contain the target molecule. A predetermined or threshold value can be obtained by various suitable methods. For example, one can incubate the capture protein-conjugated microparticles and a detection molecule with a control sample that is free of the target molecule. The average intensity of florescent emitted from all microparticles represents a predetermined value. [0036] In certain examples, RBD- Trimer or BSA-coupled beads can be read on an Acea Novocyte flow cytometer with the following gating strategy: gate beads using FSC-H vs SSC-H, eliminate doublets using FSC-H vs FSC-A, and detect PE fluorescence using FL2 (488nm excitation, 572/28nm detection). Background-subtracted MFI can be calculated by subtracting the BSA-coupled bead MFI from the RBD- or trimer-coupled bead MFI. [0037] In certain examples, ACE2, RBD or trimer protein can be tagged. In particular embodiments, the tag is biotin. Assuming that RBD or trimer protein is biotinylated in this example, biotinylated RBD or Trimer protein can be added to ACE2-coupled beads in a microwell plate. For inhibition assays, soluble unlabeled ACE2 or diluted plasma samples or other potential inhibitors of binding can be included in the incubation. Each well of the plate can be capped and mixed end- over-end at 4 °C overnight. The next day the plate can be washed and incubated with a tag binder- detectable label conjugate (e.g. Streptavidin conjugated-PE (BioLegend, #405204, USA)) in buffer protected from light at room temperature. The plate can then by analyzed for detection with flow cytometry using gating as described above. Data can be expressed either as MFI or as percent inhibition, calculated as 1- (MFI of sample)/(MFI of wells without inhibitor added). [0038] Antibodies or binding fragments thereof can be used within embodiments of the disclosure. Antibody binding fragments refer to at least one portion of an antibody, that retains the ability to specifically bind an antigen. Examples of antibody fragments include Fab, Fab′, F(ab′) ₂ , Fv fragments, single chain variable (scFv) fragments, disulfide-linked Fvs (sdFv), a Fd fragment including VH and constant CH1 domains, linear antibodies, single domain antibodies such as sdAb (either VL or VH), camelid variable heavy only (VHH) domains, and an isolated CDR or other epitope binding fragments of an antibody (Harlow et al., 1999, In: Using Antibodies: A Laboratory Manual, Cold Spring Harbor Laboratory Press, NY; Harlow et al., 1989, In: Antibodies: A Laboratory Manual, Cold Spring Harbor, N.Y.; Houston et al., 1988, Proc. Natl. Acad. Sci. USA 85:5879- 5883; Bird et al., 1988, Science 242:423-426). [0039] In particular embodiments, the microparticle-based assay is a singleplex assay. In particular embodiments, the microparticle-based assay is a multiplex assay. In particular embodiments, the microparticle-based assay is high-throughput. The term "high-throughput" refers to the ability to rapidly process multiple test samples, for example, arrays or microarrays, in an automated and/or massively parallel manner. The term "multiplex" refers to the concurrent performance of multiple experiments on a single device or in a single assay. For instance, a multiplex assay using an array according to the current disclosure allows the simultaneous detection and/or measurement of a plurality of different potential spike protein variants and/or potential binding inhibitors. [0040] In particular embodiments, a multiplex assay includes microparticles having distinguishing features to identify the class of microparticle so that a mixture of multiple sets of distinguishable microparticles is included in the assay. In particular embodiments, the microparticles are distinguishable according to their fluorescent emission spectrum, size, bar code, or other reporting entities. In particular embodiments, the microparticles are distinguishable according to their size. Microparticles of different sizes generate different forward light scatters (FSC), which can be picked up and recorded by flow cytometry. Other suitable parameters include light scatter, light emission, or combinations of light scatter and emission. Side angle light scatter varies with microparticle size, granularity, absorbance and surface roughness, while forward angle light scatter is mainly affected by size and refractive index. Thus, varying any of these qualities can serve as a means of distinguishing various groups. Light emission can be varied by labeling fluorescent materials onto detection antibodies and using fluorescent materials that have different fluorescence intensities or that emit fluorescence at different wavelengths as mentioned above, or by varying the amount of fluorescent material labeled. [0041] In particular embodiments, the multiplex assay includes two or more, three or more, four or more, five or more, six or more, seven or more, eight or more, nine or more, or ten or more classes of microparticle. In particular embodiments, the multiplex assay includes 20 or more, 30 or more, 40 or more, 50 or more, 60 or more, 70 or more, 80 or more, 90 or more, or 100 or more classes of microparticle. [0042] High throughput multiplexed bead-based assays are advantageous because they can be run in a short time period (e.g., less than 3 hours) and require little test antigen. Further, multiple test compounds can be assessed simultaneously. Additionally, pre-coated beads can be formed and stored for later use, increasing the efficiency of testing procedures. For example, particular embodiments include coupling beads to COV-2 RBD and/or COV-2 trimer and storing them for later use at 4ºC. At the time of use, coupled beads can be washed and added to wells including a tag binder- detectable label conjugate, tagged hACE2, and optionally, one or more test compounds. Wells can incubate for 1 hr followed by detection of binding based on the detectable label using flow cytometry. In another example, at the time of use coupled beads can be washed and added to wells including a test sample that may include an antibody that binds the COV-2 RBD and/or COV-2 trimer. Wells can incubate for 1 hr followed by addition of a detectable label conjugated to anti-IG antibody. Detection of binding of the anti-Ig antibody to an antibody that binds the COV-2 RBD and/or COV-2 trimer can be conducted using flow cytometry. After 30 minutes, reads can be obtained 30 minutes later. Thus, this assay can be accomplished within a time frame of 2 – 2.5 hours. [0043] In particular embodiments, the microparticles are distinguishable according to their fluorescent emission spectrum. In particular embodiments, the microparticles of each class have a fluorescent emission spectrum that is different from the emission spectra of the other microparticle classes. In particular embodiments, each different class of microparticle is pre- coated with a reagent that is specific for a different capture protein of interest, and thus different target proteins are captured from the sample to different classes of microparticles. For example, different classes of microparticles can be coupled to the trimeric spike protein, variants of the spike protein (e.g., deep mutational scanning variants), and/or truncated RBD segments of the spike protein. Different classes of microparticles could also be coupled different ACE2 variants. The target proteins are then labeled with a detection antibody with a detectable label as described previously. In particular embodiments, the detectable label includes a fluorochrome which has an emission different from any fluorescent emissions by the microparticles. In particular embodiments, the assay is read in a flow cytometer or similar instrument: each microparticle is identified as a member of a particular class, e.g., on the basis of its fluorescent emission spectrum, and whether that microparticle has the target protein captured on it is determined, e.g., by detecting the presence or absence of detectable label on the microparticle. Since the relationship between a particular microparticle class and a particular target protein is predetermined by the choice of capture protein used to coat those particles, the presence of detectable label on a given particle is indicative of the presence of a given target protein in the original sample even when a single detectable label is used to label all the analytes. See, e.g., U.S. Pat. No.5,981,180 entitled “Multiplexed analysis of clinical specimens apparatus and methods” to Chandler et al., U.S. Pat. No. 6,449,562 entitled “Multiplexed analysis of clinical specimens apparatus and methods” to Chandler et al., Kellar and Iannone (2002) “Multiplexed microsphere-based flow cytometric assays” Experimental Hematology 30:1227-1237, Fitzgerald (2001) “Assays by the score” The Scientist 15[11]:25, and Fulton et al. (1997) “Advanced multiplexed analysis with the FlowMetrix™ system” Clinical Chemistry 43:1749-1756. [0044] Particular embodiments may be practiced using Luminex® systems. The multiplex Luminex assay format differs from conventional enzyme-linked immunosorbent assay (ELISA) in that the multiplex capture antibody is attached to a polystyrene bead whereas the ELISA capture antibody is attached to the microplate well. The use of the suspension bead-based technology enables the multiplexing capabilities of the Luminex assays. The xMAP® technology uses 5.6 micron polystyrene microbeads, which are internally dyed with red and infrared fluorophores of differing intensities. Each bead is given a unique number, or bead region, allowing differentiation of one bead from another. Beads covalently bound to different specific antibodies can be mixed in the same assay, utilizing a 96- well microplate format. At the completion of the sandwich immunoassay, beads can be read, using the Luminex 100™ or Luminex 200 detection system, in single-file by dual lasers for classification and quantification of each analyte. [0045] Particular embodiments include use of a microbead-based assay wherein fluorochrome- labeled beads coupled to the COV-2 RBD and/or COV-2 trimer are incubated with tagged hACE2, a tag binder-detectable label conjugate, and test compounds. Readouts can be obtained using an analyzer, such as a laser-based instrument (e.g., a Luminex® analyzer). [0046] In particular embodiments, Ace2 is directly conjugated to microparticles using a covalent coupling reaction. A tagged SARS-CoV-2 spike “probe” is added to the Ace2-bead/analyte mixture. Following appropriate separation and/or washing steps, a tag binder-detectable label conjugate is added, which binds to the tag on the spike and produces fluorescence if binding between Ace2 and the SARS-CoV-2 spike probe is present. [0047] As a particular example, one embodiment of the current disclosure provides coupling human ACE2 to microparticles (e.g., microbeads) and tagging the COV-2 receptor binding domain (RBD) and/or the COV-2 trimer. Following incubation with a tag binder-detectable label conjugate, binding between the ACE2-coupled microparticles and the COV-2 RBD and/or COV-2 trimer can be quantified using flow cytometry to set a baseline. Experimental conditions can further include a test compound to determine if the test compound inhibits binding between ACE2-coupled microparticles and the tagged COV-2 RBD and/or COV-2 trimer as evidenced by a decreased flow cytometry signal from baseline. The test compound can include serum or plasma from subjects, including human subjects before infection with COVID-19, during active infection with COVID-19, and following recovery from infection with COVID-19. The assay may detect antibodies for potential therapeutic use when the test compound is from subjects following recovery from infection with COVID-19. The test compound can also include proteins, nucleotides, and/or or small molecules selected for screening as potential therapeutic or prophylactic compounds. [0048] Exemplary Embodiments. 1. A microparticle-based assay to: identify compounds that inhibit binding between human angiotensin-converting enzyme 2 (hACE2) and severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) spike protein or a variant or fragment thereof, the microparticle-based assay including microparticles coupled to hACE2 or microparticles coupled to the SARS-CoV-2 spike protein or a variant or fragment thereof. 2. The assay of embodiment 1, wherein microparticles within the assay are coupled to hACE2 and the assay identifies compounds that inhibit binding between hACE2 and the SARS- CoV-2 spike protein or a variant or fragment thereof and wherein the assay further includes a tagged SARS-CoV-2 spike protein or a variant or fragment thereof and a tag binder-detectable label conjugate. 3. The assay of embodiment 1 or 2, wherein the SARS-CoV-2 spike protein or variant or fragment thereof is tagged with biotin, His tag, Flag tag, Xpress tag, Avi tag, Calmodulin binding peptide (CBP) tag, Polyglutamate tag, HA tag, Myc tag, or Strep tag. 4. The assay of embodiment 2 or 3, wherein the tag binder-detectable label conjugate includes streptavidin-PE or a binding molecule that binds His tag, Flag tag, Xpress tag, Avi tag, Calmodulin binding peptide (CBP) tag, Polyglutamate tag, HA tag, Myc tag, or Strep tag bound to a detectable label. 5. The assay of any of embodiments 1-4, wherein microparticles within the assay are coupled to SARS-CoV-2 spike protein or a variant or fragment thereof and the assay identifies compounds that inhibit binding between hACE2 and the SARS-CoV-2 spike protein or a variant or fragment thereof and wherein the assay further includes a tagged hACE2 protein and a tag binder- detectable label conjugate. 6. The assay of embodiment 5, wherein the hACE2 is tagged with biotin, His tag, Flag tag, Xpress tag, Avi tag, Calmodulin binding peptide (CBP) tag, Polyglutamate tag, HA tag, Myc tag, or Strep tag. 7. The assay of embodiment 6, wherein the tag binder-detectable label conjugate includes streptavidin-PE or a binding molecule that binds His tag, Flag tag, Xpress tag, Avi tag, Calmodulin binding peptide (CBP) tag, Polyglutamate tag, HA tag, Myc tag, or Strep tag bound to a detectable label. 8. The assay of any of embodiments 1-7, wherein microparticles within the assay are coupled to the SARS-CoV-2 spike protein or a variant or fragment thereof and the assay identifies antibodies that bind the SARS-CoV-2 spike protein or a variant or fragment thereof and wherein the assay further includes an anti-immunoglobulin (Ig) antibody or binding fragment thereof linked to a detectable label. 9. The assay of embodiment 8, wherein the anti-Ig antibody or binding fragment thereof is an anti-IgG or anti-IgM antibody or binding fragment thereof. 10. The assay of any of embodiments 1-9, wherein the fragment of the SARS-CoV-2 spike protein is the receptor binding domain (RBD) fragment. 11. The assay of embodiment 10, wherein the RBD fragment has residues 319-541 of the full- length SARS-CoV-2 spike protein according to wild-type numbering. 12. The assay of any of embodiments 1-11, wherein the variant of the SARS-CoV-2 spike protein is a stabilized variant. 13. The assay of embodiment 12, wherein the stabilized variant includes K986P and V987P mutations according to wild type numbering. 14. The assay of any of embodiments 1-13, wherein the variant of the SARS-CoV-2 spike protein is an alanine scanning variant or a deep mutational scanning variant. 15. The assay of any of embodiments 1-14, wherein the microparticles include beads. 16. The assay of embodiment 15, wherein the beads include polystyrene beads, latex beads, and/or magnetic beads. 17. The assay of any of embodiments 2-16, wherein the detectable label includes a fluorophore. 18. The assay of any of embodiments 1-17, in multiplex form including different classes of microparticles, classes of microparticles within the assay coupled to hACE2, the full-length SARS- CoV-2 spike protein, a fragment of the SARS-CoV-2 spike protein, and/or a variant of the SARS- CoV-2 spike protein. 19. The assay of embodiment 18, where different classes of microparticles within the multiplex assay are coupled to the full-length SARS-CoV-2 spike protein versus a fragment of the SARS- CoV-2 spike protein. 20. Use of an assay of any of embodiments 1-19 to assess functional immunity in recovered COVID19 patients, screen plasma donations for potency in the context of convalescent plasma therapy, screen drug libraries for compounds that inhibit binding of SARS-CoV-2 to hACE2, or assess mutant spike proteins to test existing immunity against potentially emerging viral strains. 21. The use of embodiment 20, practiced in a high throughput manner. 22. The use of embodiment 21, wherein the high throughput manner simultaneously tests at least 50, at least 100, at least 500, or at least 1000 samples for: the presence of compounds that bind the SARS-CoV-2 spike protein or a variant or fragment thereof and/or that inhibit binding between the SARS-CoV-2 spike protein or a variant or fragment thereof and hACE2. 23. The use of embodiment 22, wherein the samples include human serum or plasma samples or candidate prophylactic and/or therapeutic drug compounds. 24. The use of embodiment 23, wherein the human serum or plasma samples are heat- inactivated. 25. The use of embodiment 23 or 24, wherein the candidate prophylactic and/or therapeutic drug compounds include proteins, peptides, nucleic acids, and/or small molecules. 26. The use of embodiment 25, wherein the proteins include antibodies or binding fragments thereof. 27. The use of embodiment 26, wherein the antibodies or binding fragments thereof are recombinantly produced and/or engineered. 28. The use of embodiment 27, wherein the engineered antibody includes multiple binding domains. 29. Use of the assays of any of embodiments 2-19, including co-incubating the microparticles, the tagged SARS-CoV-2 spike protein or variant or fragment thereof, and a test sample potentially including a compound that inhibits binding between the hACE2 coupled to the microparticles and the tagged SARS-CoV-2 spike protein or variant or fragment thereof. 30. The use of embodiment 29, further including co-incubating tag binder-detectable label conjugate and detecting bound tagged SARS-CoV-2 spike protein or variant or fragment thereof. 31. The use of embodiment 30, wherein the tagged SARS-CoV-2 spike protein or variant or fragment thereof is a biotinylated SARS-CoV-2 spike protein or variant or fragment thereof. 32. The use of embodiment 31, wherein the tag binder-detectable label conjugate includes streptavidin-PE. 33. Use of the assays of any of embodiments 5-19, including co-incubating the microparticles, the tagged hACE2, and a test sample potentially including a compound that inhibits binding between the SARS-CoV-2 spike protein or variant or fragment thereof coupled to the microparticles and the tagged hACE2. 34. The use of embodiment 43, further including co-incubating tag binder-detectable label conjugate and detecting bound tagged hACE2. 35. The use of embodiment 34, wherein the tagged hACE2 is biotinylated hACE2. 36. The use of embodiment 35, wherein the tag binder-detectable label conjugate includes streptavidin-PE. 37. The use of any of embodiments 30-36, wherein the detecting includes detecting a median fluorescent intensity (MFI) signal indicative of the amount of binding between hACE2 and the SARS-CoV-2 spike protein or variant or fragment thereof following the incubating. 38. Use of the assays of any of embodiments 8-19, including co-incubating the microparticles a test sample potentially including an antibody that binds the SARS-CoV-2 spike protein or variant or fragment thereof and the anti-immunoglobulin (Ig) antibody or binding fragment thereof linked to a detectable label. 39. The use of embodiment 37, further including detecting the anti-immunoglobulin (Ig) antibody or binding fragment thereof bound to the microparticles through the SARS-CoV-2 spike protein or variant or fragment thereof. 40. The use of embodiment 39, wherein the detecting includes detecting a median fluorescent intensity (MFI) signal indicative of the amount of binding between the anti-immunoglobulin (Ig) antibody or binding fragment thereof and an antibody bound to the microparticle through the SARS-CoV-2 spike protein or variant or fragment thereof. 41. The use of any of embodiments 37-40, wherein the detecting is through flow cytometry. 42. A bead-based assay to identify compounds that inhibit binding between the severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) spike protein and human angiotensin- converting enzyme 2 (hACE2). 43. The bead-based assay of embodiment 42, wherein beads within the assay are coupled with hACE2. 44. The bead-based assay of embodiment 42 or 43, wherein beads within the assay are coupled with the full-length SARS-CoV-2 spike protein, a fragment of the SARS-CoV-2 spike protein, or a variant of the SARS-CoV-2 spike protein. 45. The bead-based assay of embodiment 44, wherein the fragment of the SARS-CoV-2 spike protein is the receptor binding domain (RBD) fragment. 46. The bead-based assay of embodiment 45, wherein the RBD fragment has residues 319-541 of the full-length SARS-CoV-2 spike protein according to wild-type numbering. 47. The bead-based assay of any of embodiments 44-46, wherein the variant of the SARS-CoV- 2 spike protein is a stabilized variant. 48. The bead-based assay of embodiment 47, wherein the stabilized variant includes K986P and V987P mutations according to wild type numbering. 49. The bead-based assay of any of embodiments 44-48, wherein the variant of the SARS-CoV- 2 spike protein is an alanine scanning variant or a deep mutational scanning variant. 50. The bead-based assay of any of embodiments 44-49, wherein the beads include microparticles. 51. The bead-based assay of embodiment 50, wherein the beads include polystyrene beads, latex beads, and/or magnetic beads. 52. The bead-based assay of any of embodiments 44-51, further including biotin. 53. The bead-based assay of any of embodiments 44-52, further including phycoerythrin (PE). 54. The bead-based assay of any of embodiments 42-53, further including a biotinylated full-length SARS-CoV-2 spike protein, a biotinylated fragment of the SARS-CoV-2 spike protein, or a biotinylated variant of the SARS-CoV-2 spike protein 55. The bead-based assay of embodiment 54, wherein the biotinylated fragment of the SARS- CoV-2 spike protein is the receptor binding domain (RBD) fragment. 56. The bead-based assay of embodiment 55, wherein the biotinylated RBD fragment has residues 319-541 of the full-length SARS-CoV-2 spike protein according to wild-type numbering. 57. The bead-based assay of any of embodiments 54-56, wherein the biotinylated variant of the SARS-CoV-2 spike protein is a stabilized biotinylated variant. 58. The bead-based assay of embodiment 57, wherein the stabilized biotinylated variant includes K986P and V987P mutations according to wild type numbering. 59. The bead-based assay of any of embodiments 54-58, wherein the biotinylated variant of the SARS-CoV-2 spike protein is an alanine scanning biotinylated variant or a deep mutational scanning biotinylated variant. 60. The bead-based assay of any of embodiments 42-59, further including biotinylated hACE2. 61. The bead-based assay of any of embodiments 42-60, further including a detectable label. 62. The bead-based assay of any of embodiments 42-61, further including a protein-based binding domain coupled to a detectable label. 63. The bead-based assay of embodiment 62, wherein the protein-based binding domain includes an antibody or a binding fragment thereof. 64. The bead-based assay of embodiment 62 or 63, wherein the protein-based binding domain includes an anti-human IgG antibody or binding fragment thereof coupled to a detectable label. 65. The bead-based assay of any of embodiments 61-64, wherein the detectable label includes a fluorophore. 66. The bead-based assay of any of embodiments 42-65, further including an anti-HA tag. 67. The bead-based assay of embodiment 66, wherein the anti-HA tag is coupled to PE. 68. The bead-based assay of any of embodiments 42-67 in multiplex form including different classes of beads, classes of beads within the assay coupled to hACE2, the full-length SARS-CoV-2 spike protein, a fragment of the SARS-CoV-2 spike protein, and/or a variant of the SARS-CoV-2 spike protein. 69. The bead-based assay of embodiment 68, where different classes of beads within the multiplex assay are coupled to the full-length SARS-CoV-2 spike protein versus a fragment of the SARS-CoV-2 spike protein. 70. Use of a bead-based assay of any of embodiments 42-69 to assess functional immunity in recovered COVID19 patients, screen plasma donations for potency in the context of convalescent plasma therapy, screen drug libraries for compounds that inhibit binding of SARS-CoV-2 to hACE2, or assess mutant spike proteins to test existing immunity against potentially emerging viral strains. 71. The use of embodiment 70, practiced in a high throughput manner. 72. The use of embodiment 71, wherein the high throughput manner simultaneously tests at least 50, at least 100, at least 500, or at least 1000 samples for the presence of compounds that inhibit binding between SARS-CoV-2 to hACE2. 73. The use of embodiment 72, wherein the samples include human serum or plasma samples or candidate prophylactic and/or therapeutic drug compounds. 74. The use of embodiment 73, wherein the human serum or plasma samples are heat- inactivated. 75. The use of embodiment 73 or 74, wherein the candidate prophylactic and/or therapeutic drug compounds include proteins, peptides, nucleic acids, and/or small molecules. 76. The use of embodiment 75, wherein the proteins include antibodies or binding fragments thereof. 77. The use of embodiment 76, wherein the antibodies or binding fragments thereof are recombinantly produced and/or engineered. 78. The use of embodiment 77, wherein the engineered antibody includes multiple binding domains. [0049] Experimental Examples. IP-FCM assays were designed to detect the presence of anti- COVID antibodies in human serological samples by covalently coupling either the recombinant RBD fragment or a spike trimer construct to carboxy-modified polystyrene latex microbeads (CML). These beads were then incubated with increasing dilutions of plasma from RT-PCR- confirmed, recovered Covid-19 patients, as well as with plasma collected before 2019 as negative controls, and then with anti-human IgG antibodies conjugated to phycoerythrin (PE). As shown in FIGs.3A and 3B, high levels of anti-human IgGs were detected in the three positive samples, and low levels of non-specific background reactivity was seen in the controls, which decreased to near 0 at higher dilutions. Note that when using IP-FCM, lower reactivity at high concentrations of analyte can occur, resulting the inverted U-shaped curve shown in FIGs. 3A, 3B. 1:1000 was selected as an optimal serum dilution. Several samples were run for 1 hour or 2 hours at room temperature, or at 4C overnight, to optimize the assay. Between one hour and 2 hours, median fluorescent intensity (MFI) increased significantly in the COVID+ samples. Increasing the incubation to overnight, COVID+ signals increased slightly, but control background levels increased as well, so two hours was selected for the final assay. [0050] A larger collection of COVID+ samples, as well as 6 pre-2019 healthy controls were screened next. In COVID+ samples, immunoreactivity was higher than for the highest pre-COVID sample, indicating that all COVID patients produced strong antibody responses. One outlier, referred to as BREP026, reported only mild symptoms for a single day. It is suspected that the patient’s rtPCR test may have been a false positive. A moderate correlation between individual patient’s reactivity to RBD and Trimer (r2 = 0.50) was observed. [0051] To determine if the presence of serum IgG might correlate with inhibition of viral binding to its receptor, an IP-FCM assay was designed to measure the binding of ACE2 and SARS-CoV- 2 spike proteins. Human ACE2 protein was coupled to CML beads and incubated with biotinylated RBD or Trimer, followed by incubation with Streptavidin-PE. As an additional specificity control, an excess of soluble, unlabeled human ACE2 was included to compete for bead-bound ACE2 and inhibit binding. FIG.4A shows strong binding of both RBD and Trimer to ACE2 beads, which is inhibited by unlabeled ACE2. The EC50 was determined by serial dilution of the Trimer (FIG. 4B, EC50 = 1:473 dilution) and RBD (FIG.4C, 1:1477 dilution), and the inhibition assay was run at twice the EC50 to maximize the potential ability to detect serum-mediated inhibition. Two positive and two negative serum samples were next selected and serial dilutions of serum were performed, keeping the number of beads and the concentration of Trimer (1:1000) or RBD (1:3000) constant. For the trimer, almost complete inhibition of binding occurred at dilutions higher than 1:100, with non-specific control serum inhibition dropping to zero by 1:50 (FIG.4D). For the RBD, variable levels of inhibition were observed in the COVID+ samples, with non-specific control inhibition dropping below 10% at 1:50 (FIG. 4E). 1:50 was therefore selected as the best combination of high signal and low non-specific background. [0052] Covid-19 positive and negative patient plasma was next tested for its ability to inhibit the ACE2 Spike interaction. In the trimer assay (FIG.5A), pre-COVID serum significantly reduced the MFI of ACE2-trimer binding, presumably through non-specific serum factors, leading to up to 70% inhibition (FIG.5B). However, 13/14 COVID+ samples showed greater than 85% inhibition, with the single BREP026 sample that was negative for COVID antibodies showing MFI and percent inhibition levels that overlapped with control values. Using the RBD assay, pre-covid samples slightly and non-significantly reduced the MFI of ACE2-RDB binding (FIG. 5C), and there were two distinct populations of COVID+ samples; five samples showed >50% inhibition (dotted line in FIG. 5D), while the remainder clustered with controls. In fact, when COVID+ samples were separated into “responders” and “non-responders” using an arbitrary 50% inhibition cut-off, there was no significant difference between the non-responders and control, but the responders were significantly different (P<0.001, FIG.5E). [0053] In order to confirm the specificity of the inhibition assay, the serum of one precovid control and three COVID+ samples (2 RBD-“responders”, one RBD “non-responder”) were depleted by incubating them with large numbers of Trimer-conjugated beads for three consecutive overnight incubations until the level of IgG detected on the beads plateaued at a background level, or with bovine-serum-albumin (BSA)-coated beads as a negative control. In the trimer inhibition assay, all three COVID+ un-depleted samples strongly inhibited ACE2-Trimer; inhibition was not significantly different after BSA depletion but was significantly reduced to control levels by Trimer depletion (FIG.6A). In the RBD depletion assay, the two COVID+ “responders” showed moderate levels of inhibition before depletion; inhibition was slightly (P<0.05) reduced in one of two samples by BSA and was reduced to zero following depletion (P<0.01, FIG. 6A). For the COVID+ non- responder and the pre-COVID control, the percent inhibition was not significantly different among depletion conditions. [0054] It was next assessed if serum IgG levels correlated with inhibition of ACE2 biding. For the Trimer, the % inhibition in the ACE2 inhibition assay correlated with levels of anti-Trimer IgG measured in plasma (r2 = 0.52, slope of the regression line significantly non-zero p<0.005, FIG. 7A). However, for the RBD, there was no correlation between RBS levels and % inhibition (r2 = 0.01, and the slope of the regression line was not significantly different from 0, FIG.7B). Even if the analysis is limited to “responders”, there is no correlation between anti-RBD IgG levels and % inhibition. Finally, the percent inhibition of COVID+ samples in the RBD and Trimer assays was compared, and no correlation between the two measures was detected (r2 = 0.13, slope of the regression line not significant, FIG.7C). [0055] Methods. Protein purification: The RBD construct was cloned in an in-house vector, and the trimer and Ace2 constructs were obtained from the McLellan Group. Proteins were expressed in 293F cells using lipid-mediated transduction, purified using immobilized metal ion chromatography, and stored in PBS. [0056] CML Bead Coupling: To couple RBD, ACE2 and Trimer proteins to flow cytometry- compatible beads, the protocols published in Davis 2010 (hwww.jove.com/video/2066/ip-fcm- immunoprecipitation-detected-by-flow-cytometry)d were followed. Briefly, 50 μL of CML beads (Invitrogen #C37255, USA) or 250ul of MagPlex Microspheres (Luminex #MC100XX-01, USA) were washed 3 times with 500 uL of room temperature MES (50 mM MES (2-(N- morpholino)ethanesulfonic acid), pH 6.0, 1 mM EDTA, in ddH20, stored at 4˚C, used at RT). Beads were spun down for 1 minute at 13,000 x g at 4 °C and supernatant discarded after each wash. The CML beads were then resuspended in 50uL of MES and activated with 20 μL of 50mg/mL EDAC (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide HCl; Pierce, USA), freshly dissolved in MES from powder stored at -20 ˚C. This 70 μL of CML bead, MES, and EDAC was mixed for 15 minutes by continuously pipetting gently up and down at room temperature. The beads were washed three times with 0.5 mL of PBS. After the third wash the activated bead pellet was resuspended in a 100 μL solution containing 25 μg of either RBD, Trimer or ACE2 protein in PBS and gently mixed for 3 hours at room temperature at 1400 rpm on a pulsing vortexer. The coupled beads were then washed 3 times in 0.5 mL of PBS and stored in 100 uL of Blocking Storage Solution (1% BSA in PBS, 0.01% Sodium Azide) at 4˚C until use. Successful coupling was confirmed by staining 0.5 uL coupled beads with PE-conjugated anti-HIS tag antibodies (Santa Cruz) and compared to positive and negative controls by flow cytometry. [0057] IgG Detection with IP-FCM: IP-FCM was performed as described in Smith et al., PLoS One 2012;7(9):e45722 (doi: 10.1371/journal.pone.0045722). Patient plasma from both SARS- CoV-2 positive and negative patients was heated to 56°C for 1 hour, then spun at 13,000 x g for 10 minutes at 4°C. The supernatant plasma was then diluted (typically at 1:1000) in cold Fly-P Buffer (50 mM Tris pH 7.4, 100 mM NaCl, 1% bovine serum albumin, and 0.01% sodium azide) and distributed into wells of a 96-well plate at a volume of 50 μL per well, in duplicate. 5 x 10 ⁴ RBD- or Trimer-conjugated CML beads were added to each well. The wells of the 96-well plate were then capped, and the plate left to rotate overnight at 4°C. The next day, the plate was spun at 3500 RPM to pellet the CML beads and the supernatant was discarded. The beads were washed twice with 125 ul of cold Fly-P Buffer per well and incubated with 50 μL of 1:200 anti- Human IgG-PE (Jackson ImmunoResearch, #709-116-149, lot 145536, USA) in Fly-P Buffer protected from light for 30 minutes at room temperature. The plate was washed 2 more times with 125 μL of ice-cold Fly-P Buffer and the samples were resuspended in 50 μL of cold Fly-P Buffer. All plasma samples were also run in parallel using BSA-coupled CML beads to determine the baseline nonspecific signal generated from each sample, which varied greatly between individuals from 10 ³ -10 ⁵ MFI units, but was consistent for each individual. RBD- Trimer or BSA-coupled beads were then read on an Acea Novocyte flow cytometer with the following gating strategy: gate beads using FSC-H vs SSC-H, eliminate doublets using FSC-H vs FSC-A, and detect PE fluorescence using FL2 (488nm excitation, 572/28nm detection). Background-subtracted MFI was calculated for each individual by subtracting the BSA-coupled bead MFI from the RBD- or trimer-coupled bead MFI. [0058] ACE2-Spike binding assay: RBD or trimer protein was biotinylated by adding 1ul of freshly- dissolved sulfo-NHS-Biotin (ThermoScientific, #21217, USA) for 30 minutes on ice. The reaction was quenched with TRIS-HCL and excess biotin removed by three PBS washes in a 10K MWCO Amicon spin filter (Millipore). Biotinylated RBD or Trimer protein was added to 5 x 10 ⁴ ACE2- coupled CML beads in a total volume of 50 μL, in duplicate. For inhibition assays, soluble unlabeled ACE2 or diluted plasma samples prepared as above were included in the incubation, maintaining a final reaction volume of 50uL. Plasma was diluted 1:50 in FlyP buffer unless otherwise indicated. Each well of the plate was capped mixed end-over-end at 4 °C overnight. The next day the plate was washed twice with 125 μL of cold Fly-P Buffer and incubated with 50 μL of 1:200 Streptavidin conjugated-PE (BioLegend, #405204, USA) in Fly-P Buffer protected from light for 30 minutes at room temperature. The plate was washed 2 more times with 125 μL of cold Fly-P Buffer and samples were resuspended in 50 μL of cold Fly-P Buffer for detection on the flow cytometer with gating as above. Data were expressed either as MFI or as percent inhibition, calculated as 1- (MFI of sample)/(MFI of wells without inhibitor added). [0059] Closing Paragraphs. Variants of the sequences disclosed and referenced herein are also included. Guidance in determining which amino acid residues can be substituted, inserted, or deleted without abolishing biological activity can be found using computer programs well known in the art, such as DNASTAR™ (Madison, Wisconsin) software. Preferably, amino acid changes in the protein variants disclosed herein are conservative amino acid changes, i.e., substitutions of similarly charged or uncharged amino acids. A conservative amino acid change involves substitution of one of a family of amino acids which are related in their side chains. [0060] In a peptide or protein, suitable conservative substitutions of amino acids are known to those of skill in this art and generally can be made without altering a biological activity of a resulting molecule. Those of skill in this art recognize that, in general, single amino acid substitutions in non-essential regions of a polypeptide do not substantially alter biological activity (see, e.g., Watson et al. Molecular Biology of the Gene, 4th Edition, 1987, The Benjamin/Cummings Pub. Co., p.224). Naturally occurring amino acids are generally divided into conservative substitution families as follows: Group 1: Alanine (Ala), Glycine (Gly), Serine (Ser), and Threonine (Thr); Group 2: (acidic): Aspartic acid (Asp), and Glutamic acid (Glu); Group 3: (acidic; also classified as polar, negatively charged residues and their amides): Asparagine (Asn), Glutamine (Gln), Asp, and Glu; Group 4: Gln and Asn; Group 5: (basic; also classified as polar, positively charged residues): Arginine (Arg), Lysine (Lys), and Histidine (His); Group 6 (large aliphatic, nonpolar residues): Isoleucine (Ile), Leucine (Leu), Methionine (Met), Valine (Val) and Cysteine (Cys); Group 7 (uncharged polar): Tyrosine (Tyr), Gly, Asn, Gln, Cys, Ser, and Thr; Group 8 (large aromatic residues): Phenylalanine (Phe), Tryptophan (Trp), and Tyr; Group 9 (non- polar): Proline (Pro), Ala, Val, Leu, Ile, Phe, Met, and Trp; Group 11 (aliphatic): Gly, Ala, Val, Leu, and Ile; Group 10 (small aliphatic, nonpolar or slightly polar residues): Ala, Ser, Thr, Pro, and Gly; and Group 12 (sulfur-containing): Met and Cys. Additional information can be found in Creighton (1984) Proteins, W.H. Freeman and Company. [0061] In making such changes, the hydropathic index of amino acids may be considered. The importance of the hydropathic amino acid index in conferring interactive biologic function on a protein is generally understood in the art (Kyte and Doolittle, 1982, J. Mol. Biol.157(1), 105-32). Each amino acid has been assigned a hydropathic index on the basis of its hydrophobicity and charge characteristics (Kyte and Doolittle, 1982). These values are: Ile (+4.5); Val (+4.2); Leu (+3.8); Phe (+2.8); Cys (+2.5); Met (+1.9); Ala (+1.8); Gly (−0.4); Thr (−0.7); Ser (−0.8); Trp (−0.9); Tyr (−1.3); Pro (−1.6); His (−3.2); Glutamate (−3.5); Gln (−3.5); aspartate (−3.5); Asn (−3.5); Lys (−3.9); and Arg (−4.5). [0062] It is known in the art that certain amino acids may be substituted by other amino acids having a similar hydropathic index or score and still result in a protein with similar biological activity, i.e., still obtain a biological functionally equivalent protein. In making such changes, the substitution of amino acids whose hydropathic indices are within ±2 is preferred, those within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred. It is also understood in the art that the substitution of like amino acids can be made effectively on the basis of hydrophilicity. [0063] As detailed in US 4,554,101, the following hydrophilicity values have been assigned to amino acid residues: Arg (+3.0); Lys (+3.0); aspartate (+3.0±1); glutamate (+3.0±1); Ser (+0.3); Asn (+0.2); Gln (+0.2); Gly (0); Thr (−0.4); Pro (−0.5±1); Ala (−0.5); His (−0.5); Cys (−1.0); Met (−1.3); Val (−1.5); Leu (−1.8); Ile (−1.8); Tyr (−2.3); Phe (−2.5); Trp (−3.4). It is understood that an amino acid can be substituted for another having a similar hydrophilicity value and still obtain a biologically equivalent, and in particular, an immunologically equivalent protein. In such changes, the substitution of amino acids whose hydrophilicity values are within ±2 is preferred, those within ±1 are particularly preferred, and those within ±0.5 are even more particularly preferred. [0064] As outlined above, amino acid substitutions may be based on the relative similarity of the amino acid side-chain substituents, for example, their hydrophobicity, hydrophilicity, charge, size, and the like. As indicated elsewhere, variants of gene sequences can include codon optimized variants, sequence polymorphisms, splice variants, and/or mutations that do not affect the function of an encoded product to a statistically-significant degree. [0065] Variants of the protein, nucleic acid, and gene sequences disclosed herein also include sequences with at least 70% sequence identity, 80% sequence identity, 85% sequence, 90% sequence identity, 95% sequence identity, 96% sequence identity, 97% sequence identity, 98% sequence identity, or 99% sequence identity to the protein, nucleic acid, or gene sequences disclosed herein. [0066] “% sequence identity” refers to a relationship between two or more sequences, as determined by comparing the sequences. In the art, "identity" also means the degree of sequence relatedness between protein, nucleic acid, or gene sequences as determined by the match between strings of such sequences. "Identity" (often referred to as "similarity") can be readily calculated by known methods, including those described in: Computational Molecular Biology (Lesk, A. M., ed.) Oxford University Press, NY (1988); Biocomputing: Informatics and Genome Projects (Smith, D. W., ed.) Academic Press, NY (1994); Computer Analysis of Sequence Data, Part I (Griffin, A. M., and Griffin, H. G., eds.) Humana Press, NJ (1994); Sequence Analysis in Molecular Biology (Von Heijne, G., ed.) Academic Press (1987); and Sequence Analysis Primer (Gribskov, M. and Devereux, J., eds.) Oxford University Press, NY (1992). Preferred methods to determine identity are designed to give the best match between the sequences tested. Methods to determine identity and similarity are codified in publicly available computer programs. Sequence alignments and percent identity calculations may be performed using the Megalign program of the LASERGENE bioinformatics computing suite (DNASTAR, Inc., Madison, Wisconsin). Multiple alignment of the sequences can also be performed using the Clustal method of alignment (Higgins and Sharp CABIOS, 5, 151-153 (1989) with default parameters (GAP PENALTY=10, GAP LENGTH PENALTY=10). Relevant programs also include the GCG suite of programs (Wisconsin Package Version 9.0, Genetics Computer Group (GCG), Madison, Wisconsin); BLASTP, BLASTN, BLASTX (Altschul, et al., J. Mol. Biol. 215:403-410 (1990); DNASTAR (DNASTAR, Inc., Madison, Wisconsin); and the FASTA program incorporating the Smith-Waterman algorithm (Pearson, Comput. Methods Genome Res., [Proc. Int. Symp.] (1994), Meeting Date 1992, 111-20. Editor(s): Suhai, Sandor. Publisher: Plenum, New York, N.Y.. Within the context of this disclosure it will be understood that where sequence analysis software is used for analysis, the results of the analysis are based on the "default values" of the program referenced. As used herein "default values" will mean any set of values or parameters, which originally load with the software when first initialized. [0067] Variants also include nucleic acid molecules that hybridizes under stringent hybridization conditions to a sequence disclosed herein and provide the same function as the reference sequence. Exemplary stringent hybridization conditions include an overnight incubation at 42 °C in a solution including 50% formamide, 5XSSC (750 mM NaCl, 75 mM trisodium citrate), 50 mM sodium phosphate (pH 7.6), 5XDenhardt's solution, 10% dextran sulfate, and 20 µg/ml denatured, sheared salmon sperm DNA, followed by washing the filters in 0.1XSSC at 50 °C. Changes in the stringency of hybridization and signal detection are primarily accomplished through the manipulation of formamide concentration (lower percentages of formamide result in lowered stringency); salt conditions, or temperature. For example, moderately high stringency conditions include an overnight incubation at 37°C in a solution including 6XSSPE (20XSSPE=3M NaCl; 0.2M NaH2PO4; 0.02M EDTA, pH 7.4), 0.5% SDS, 30% formamide, 100 µg/ml salmon sperm blocking DNA; followed by washes at 50 °C with 1XSSPE, 0.1% SDS. In addition, to achieve even lower stringency, washes performed following stringent hybridization can be done at higher salt concentrations (e.g. 5XSSC). Variations in the above conditions may be accomplished through the inclusion and/or substitution of alternate blocking reagents used to suppress background in hybridization experiments. Typical blocking reagents include Denhardt's reagent, BLOTTO, heparin, denatured salmon sperm DNA, and commercially available proprietary formulations. The inclusion of specific blocking reagents may require modification of the hybridization conditions described above, due to problems with compatibility. _[0068] ^{"Specifically binds" refers to an association of a binding domain (of, for example, a CAR} binding domain or a nanoparticle selected cell targeting ligand) to its cognate binding molecule with an affinity or Ka (i.e., an equilibrium association constant of a particular binding interaction with units of 1/M) equal to or greater than 10 ⁵ M ^-1 , while not significantly associating with any other molecules or components in a relevant environment sample. “Specifically binds” is also referred to as “binds” herein. Binding domains may be classified as "high affinity" or "low affinity". In particular embodiments, "high affinity" binding domains refer to those binding domains with a Ka of at least 10 ⁷ M-1, at least 10 ⁸ M-1, at least 10 ⁹ M ^-1 , at least 10 ¹⁰ M ^-1 , at least 10 ¹¹ M ^-1 , at least 10 ¹² M ^-1 , or at least 10 ¹³ M ^-1 . In particular embodiments, "low affinity" binding domains refer to those binding domains with a Ka of up to 10 ⁷ M ^-1 , up to 10 ⁶ M ^-1 , up to 10 ⁵ M ^-1 . Alternatively, affinity may be defined as an equilibrium dissociation constant (Kd) of a particular binding interaction with units of M (e.g., 10 ^-5 M to 10 ^-13 M). In certain embodiments, a binding domain may have "enhanced affinity," which refers to a selected or engineered binding domains with stronger binding to a cognate binding molecule than a wild type (or parent) binding domain. For example, enhanced affinity may be due to a Ka (equilibrium association constant) for the cognate binding molecule that is higher than the reference binding domain or due to a Kd (dissociation constant) for the cognate binding molecule that is less than that of the reference binding domain, or due to an off- rate (Koff) for the cognate binding molecule that is less than that of the reference binding domain. A variety of assays are known for detecting binding domains that specifically bind a particular cognate binding molecule as well as determining binding affinities, such as Western blot, ELISA, and BIACORE® analysis (see also, e.g., Scatchard, et al., 1949, Ann. N.Y. Acad. Sci. 51:660; and US 5,283,173, US 5,468,614, or the equivalent). [0069] Unless otherwise indicated, the practice of the present disclosure can employ conventional techniques of immunology, molecular biology, microbiology, cell biology and recombinant DNA. These methods are described in the following publications. See, e.g., Sambrook, et al. Molecular Cloning: A Laboratory Manual, 2nd Edition (1989); F. M. Ausubel, et al. eds., Current Protocols in Molecular Biology, (1987); the series Methods IN Enzymology (Academic Press, Inc.); M. MacPherson, et al., PCR: A Practical Approach, IRL Press at Oxford University Press (1991); MacPherson et al., eds. PCR 2: Practical Approach, (1995); Harlow and Lane, eds. Antibodies, A Laboratory Manual, (1988); and R. I. Freshney, ed. Animal Cell Culture (1987). [0070] As will be understood by one of ordinary skill in the art, each embodiment disclosed herein can comprise, consist essentially of or consist of its particular stated element, step, ingredient or component. Thus, the terms “include” or “including” should be interpreted to recite: “comprise, consist of, or consist essentially of.” The transition term “comprise” or “comprises” means has, but is not limited to, and allows for the inclusion of unspecified elements, steps, ingredients, or components, even in major amounts. The transitional phrase “consisting of” excludes any element, step, ingredient or component not specified. The transition phrase “consisting essentially of” limits the scope of the embodiment to the specified elements, steps, ingredients or components and to those that do not materially affect the embodiment. A material effect would cause a statistically significant reduction in the ability to detect a compound that inhibits binding between hACE2 and the SARS-CoV-2 spike protein utilizing a bead-based assay as described herein. [0071] Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present invention. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. When further clarity is required, the term “about” has the meaning reasonably ascribed to it by a person skilled in the art when used in conjunction with a stated numerical value or range, i.e. denoting somewhat more or somewhat less than the stated value or range, to within a range of ±20% of the stated value; ±19% of the stated value; ±18% of the stated value; ±17% of the stated value; ±16% of the stated value; ±15% of the stated value; ±14% of the stated value; ±13% of the stated value; ±12% of the stated value; ±11% of the stated value; ±10% of the stated value; ±9% of the stated value; ±8% of the stated value; ±7% of the stated value; ±6% of the stated value; ±5% of the stated value; ±4% of the stated value; ±3% of the stated value; ±2% of the stated value; or ±1% of the stated value. [0072] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements. [0073] The terms “a,” “an,” “the” and similar referents used in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. [0074] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member may be referred to and claimed individually or in any combination with other members of the group or other elements found herein. It is anticipated that one or more members of a group may be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is deemed to contain the group as modified thus fulfilling the written description of all Markush groups used in the appended claims. [0075] Certain embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Of course, variations on these described embodiments will become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventor expects skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. [0076] Furthermore, numerous references have been made to patents, printed publications, journal articles and other written text throughout this specification (referenced materials herein). Each of the referenced materials are individually incorporated herein by reference in their entirety for their referenced teaching. [0077] In closing, it is to be understood that the embodiments of the invention disclosed herein are illustrative of the principles of the present invention. Other modifications that may be employed are within the scope of the invention. Thus, by way of example, but not of limitation, alternative configurations of the present invention may be utilized in accordance with the teachings herein. Accordingly, the present invention is not limited to that precisely as shown and described. [0078] The particulars shown herein are by way of example and for purposes of illustrative discussion of the preferred embodiments of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of various embodiments of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for the fundamental understanding of the invention, the description taken with the drawings and/or examples making apparent to those skilled in the art how the several forms of the invention may be embodied in practice. [0079] Definitions and explanations used in the present disclosure are meant and intended to be controlling in any future construction unless clearly and unambiguously modified in the examples or when application of the meaning renders any construction meaningless or essentially meaningless. In cases where the construction of the term would render it meaningless or essentially meaningless, the definition should be taken from Webster's Dictionary, 3rd Edition or a dictionary known to those of ordinary skill in the art, such as the Oxford Dictionary of Biochemistry and Molecular Biology (Eds. Attwood T et al., Oxford University Press, Oxford, 2006).