{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:22:25Z","timestamp":1785424945454,"version":"3.56.0"},"reference-count":115,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T00:00:00Z","timestamp":1777334400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Cancer Institute","award":["75N91019D00024"],"award-info":[{"award-number":["75N91019D00024"]}]},{"award":["75N91019D00024"],"award-info":[{"award-number":["75N91019D00024"]}],"id":[{"id":"https:\/\/ror.org\/02t771148","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>The COVID-19 pandemic highlighted the critical role of serological assays in understanding antiviral immune responses, monitoring vaccine efficacy, and informing public health strategies. This review provides a comprehensive overview of commonly used SARS-CoV-2 antibody detection methods, focusing on binding and neutralization assays. Antibody binding assays, including enzyme-linked immunosorbent assays (ELISAs), chemiluminescence immunoassays (CLIAs), lateral flow immunoassays (LFAs), and multiplex platforms, enable the rapid and high-throughput detection of immunoglobulin isotypes against various viral antigens. Neutralization assays, including live-virus, pseudovirus (PsV), and surrogate assays, offer functional insights into the ability of antibodies to prevent viral entry, though they often require higher biosafety levels and optimization. Serological assays, primarily antibody binding assays and several surrogate neutralization assays, received Emergency Use Authorization (EUA) during the pandemic, supporting seroprevalence efforts. Antibody binding assays and neutralization assays were also widely used in vaccine immunogenicity studies. Despite many standardization initiatives, assay standardization and data harmonization remain challenging and require further efforts. The choice of assay should be guided by study goals: antibody binding assays are preferred for high-throughput monitoring and epidemiological studies, while neutralization assays are essential for assessing functional immunity and variant-specific neutralization and protection.<\/jats:p>","DOI":"10.3390\/vaccines14050395","type":"journal-article","created":{"date-parts":[[2026,4,28]],"date-time":"2026-04-28T13:26:41Z","timestamp":1777382801000},"page":"395","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Measuring Humoral Immune Responses to SARS-CoV-2: A Comprehensive Review of Serological Assays"],"prefix":"10.3390","volume":"14","author":[{"given":"Huijing","family":"Xue","sequence":"first","affiliation":[{"name":"Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-4573-3607","authenticated-orcid":false,"given":"Katarzyna","family":"Haynesworth","sequence":"additional","affiliation":[{"name":"Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Heidi A.","family":"Hempel","sequence":"additional","affiliation":[{"name":"Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Troy J.","family":"Kemp","sequence":"additional","affiliation":[{"name":"Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ligia A.","family":"Pinto","sequence":"additional","affiliation":[{"name":"Vaccine, Immunity and Cancer Directorate, Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,28]]},"reference":[{"key":"ref_1","unstructured":"WHO (2025, October 22). WHO COVID-19 Dashboard. Available online: https:\/\/data.who.int\/dashboards\/covid19\/cases."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e048391","DOI":"10.1136\/bmjopen-2020-048391","article-title":"Multiorgan impairment in low-risk individuals with post-COVID-19 syndrome: A prospective, community-based study","volume":"11","author":"Dennis","year":"2021","journal-title":"BMJ Open"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1038\/s41579-022-00713-0","article-title":"SARS-CoV-2 pathogenesis","volume":"20","author":"Lamers","year":"2022","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"90","DOI":"10.1007\/s42399-022-01167-4","article-title":"Post-acute sequelae of COVID-19 (PASC): A meta-narrative review of pathophysiology, prevalence, and management","volume":"4","author":"Munipalli","year":"2022","journal-title":"SN Compr. Clin. Med."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"685","DOI":"10.1038\/s41579-021-00630-8","article-title":"Structural biology of SARS-CoV-2 and implications for therapeutic development","volume":"19","author":"Yang","year":"2021","journal-title":"Nat. Rev. Microbiol."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e100","DOI":"10.1002\/cpmc.100","article-title":"SARS-CoV-2 Seroconversion in Humans: A Detailed Protocol for a Serological Assay, Antigen Production, and Test Setup","volume":"57","author":"Stadlbauer","year":"2020","journal-title":"Curr. Protoc. Microbiol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"e1312","DOI":"10.1002\/cti2.1312","article-title":"Systematic evaluation of SARS-CoV-2 antigens enables a highly specific and sensitive multiplex serological COVID-19 assay","volume":"10","author":"Hober","year":"2021","journal-title":"Clin. Transl. Immunol."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Shengule, S., Alai, S., Bhandare, S., Patil, S., Gautam, M., Mangaonkar, B., Gupta, S., Shaligram, U., and Gairola, S. (2024). Validation and Suitability Assessment of Multiplex Mesoscale Discovery Immunogenicity Assay for Establishing Serological Signatures Using Vaccinated, Non-Vaccinated and Breakthrough SARS-CoV-2 Infected Cases. Vaccines, 12.","DOI":"10.20944\/preprints202401.0615.v1"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"529","DOI":"10.1016\/j.chom.2021.03.002","article-title":"SARS-CoV-2 variant B.1.1.7 is susceptible to neutralizing antibodies elicited by ancestral spike vaccines","volume":"29","author":"Shen","year":"2021","journal-title":"Cell Host Microbe"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"1073","DOI":"10.1038\/s41587-020-0631-z","article-title":"A SARS-CoV-2 surrogate virus neutralization test based on antibody-mediated blockage of ACE2-spike protein-protein interaction","volume":"38","author":"Tan","year":"2020","journal-title":"Nat. Biotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e0039324","DOI":"10.1128\/msphere.00393-24","article-title":"Analytical measuring interval, linearity, and precision of serology assays for detection of SARS-CoV-2 antibodies according to CLSI guidelines","volume":"9","author":"Haynesworth","year":"2024","journal-title":"mSphere"},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Amellal, H., Assaid, N., Charoute, H., Akarid, K., Maaroufi, A., Ezzikouri, S., and Sarih, M. (2023). Kinetics of specific anti-SARS-CoV-2 IgM, IgA, and IgG responses during the first 12 months after SARS-CoV-2 infection: A prospective longitudinal study. PLoS ONE, 18.","DOI":"10.1371\/journal.pone.0288557"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e0045821","DOI":"10.1128\/Spectrum.00458-21","article-title":"Evaluation of a SARS-CoV-2 Capture IgM Antibody Assay in Convalescent Sera","volume":"9","author":"Ha","year":"2021","journal-title":"Microbiol. Spectr."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"112832","DOI":"10.1016\/j.jim.2020.112832","article-title":"SARS-CoV-2-specific ELISA development","volume":"484-485","author":"Roy","year":"2020","journal-title":"J. Immunol. Methods"},{"key":"ref_15","unstructured":"NIBSC (2025, October 29). WHO International Standard First WHO International Standard for Anti-SARS-CoV-2 Immunoglobulin (Human) NIBSC Code: 20\/136 Instructions for Use (Version 2.0, Dated 17\/12\/2020), Available online: https:\/\/nibsc.org\/documents\/ifu\/20-136.pdf."},{"key":"ref_16","unstructured":"U.S. Food & Drug Administration (2025, May 19). EUA Authorized Serology Test Performance, Available online: https:\/\/www.fda.gov\/medical-devices\/covid-19-emergency-use-authorizations-medical-devices\/eua-authorized-serology-test-performance."},{"key":"ref_17","unstructured":"U.S. Food & Drug Administration (2025, October 29). In Vitro Diagnostics Emergency Use Authorizations (EUAs)\u2014Serology and Other Adaptive Immune Response Tests for SARS-CoV-2, Available online: https:\/\/www.fda.gov\/medical-devices\/covid-19-emergency-use-authorizations-medical-devices\/in-vitro-diagnostics-emergency-use-authorizations-euas-serology-and-other-adaptive-immune-response."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"e02026-20","DOI":"10.1128\/JCM.02026-20","article-title":"Comparison of Antibody Class-Specific SARS-CoV-2 Serologies for the Diagnosis of Acute COVID-19","volume":"59","author":"Verkerke","year":"2021","journal-title":"J. Clin. Microbiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"101474","DOI":"10.1016\/j.xcrm.2024.101474","article-title":"SARS-CoV-2 BA.1 and BA.2 breakthrough infections boost antibody responses to early Omicron subvariants but not BQ.1.1 or XBB.1.5","volume":"5","author":"Abbad","year":"2024","journal-title":"Cell Rep. Med."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3","DOI":"10.21037\/jlpm-20-105","article-title":"Analytical assessment of Beckman Coulter Access anti-SARS-CoV-2 IgG immunoassay","volume":"6","author":"Ruscio","year":"2020","journal-title":"J. Lab. Precis. Med."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"98","DOI":"10.1136\/emermed-2024-214177","article-title":"Multiplex lateral flow test sensitivity and specificity in detecting influenza A, B and SARS-CoV-2 in adult patients in a UK emergency department","volume":"42","author":"Batra","year":"2025","journal-title":"Emerg. Med. J."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"479","DOI":"10.1007\/978-3-031-28012-2_26","article-title":"Multiplex Immunoassay Approaches Using Luminex(R) xMAP(R) Technology for the Study of COVID-19 Disease","volume":"1412","author":"Das","year":"2023","journal-title":"Adv. Exp. Med. Biol."},{"key":"ref_23","unstructured":"Thermo Fisher Scientific (2025, October 29). Coronavirus Serology Assays: Immunoassays for Research. Available online: https:\/\/www.thermofisher.com\/us\/en\/home\/life-science\/antibodies\/immunoassays\/immunoassay-research-areas\/coronavirus-serology-assays.html."},{"key":"ref_24","unstructured":"MSD (2025, October 29). Tools for COVID-19 Research. Available online: https:\/\/www.mesoscale.com\/en\/products_and_services\/assay_kits\/covid-19."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"e0370922","DOI":"10.1128\/spectrum.03709-22","article-title":"Quantification of Severe Acute Respiratory Syndrome Coronavirus 2 Binding Antibody Levels To Assess Infection and Vaccine-Induced Immunity Using WHO Standards","volume":"11","author":"Pernet","year":"2023","journal-title":"Microbiol. Spectr."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"100354","DOI":"10.1016\/j.xcrm.2021.100354","article-title":"Longitudinal analysis shows durable and broad immune memory after SARS-CoV-2 infection with persisting antibody responses and memory B and T cells","volume":"2","author":"Cohen","year":"2021","journal-title":"Cell Rep. Med."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"845","DOI":"10.1038\/s41591-020-0897-1","article-title":"Antibody responses to SARS-CoV-2 in patients with COVID-19","volume":"26","author":"Long","year":"2020","journal-title":"Nat. Med."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1093\/infdis\/jiaa273","article-title":"Sensitivity in Detection of Antibodies to Nucleocapsid and Spike Proteins of Severe Acute Respiratory Syndrome Coronavirus 2 in Patients With Coronavirus Disease 2019","volume":"222","author":"Burbelo","year":"2020","journal-title":"J. Infect. Dis."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"e0179623","DOI":"10.1128\/spectrum.01796-23","article-title":"Distinguishing SARS-CoV-2 infection and vaccine responses up to 18 months post-infection using nucleocapsid protein and receptor-binding domain antibodies","volume":"11","author":"Jarlhelt","year":"2023","journal-title":"Microbiol. Spectr."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"105621","DOI":"10.1016\/j.jcv.2023.105621","article-title":"Serological assays for differentiating natural COVID-19 infection from vaccine induced immunity","volume":"170","author":"Cheng","year":"2024","journal-title":"J. Clin. Virol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"116","DOI":"10.1016\/j.ijid.2021.12.316","article-title":"An automated chemiluminescent immunoassay (CLIA) detects SARS-CoV-2 neutralizing antibody levels in COVID-19 patients and vaccinees","volume":"115","author":"Liu","year":"2022","journal-title":"Int. J. Infect. Dis."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1081","DOI":"10.1515\/cclm-2020-0443","article-title":"Analytical performances of a chemiluminescence immunoassay for SARS-CoV-2 IgM\/IgG and antibody kinetics","volume":"58","author":"Padoan","year":"2020","journal-title":"Clin. Chem. Lab. Med."},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Vilca-Alosilla, J.J., Candia-Puma, M.A., Coronel-Monje, K., Goyzueta-Mamani, L.D., Galdino, A.S., Machado-de-Avila, R.A., Giunchetti, R.C., Ferraz Coelho, E.A., and Chavez-Fumagalli, M.A. (2023). A Systematic Review and Meta-Analysis Comparing the Diagnostic Accuracy Tests of COVID-19. Diagnostics, 13.","DOI":"10.3390\/diagnostics13091549"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Zheng, X., Duan, R.H., Gong, F., Wei, X., Dong, Y., Chen, R., Yue Liang, M., Tang, C., and Lu, L. (2022). Accuracy of serological tests for COVID-19: A systematic review and meta-analysis. Front. Public Health, 10.","DOI":"10.3389\/fpubh.2022.923525"},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Speletas, M., Kyritsi, M.A., Vontas, A., Theodoridou, A., Chrysanthidis, T., Hatzianastasiou, S., Petinaki, E., and Hadjichristodoulou, C. (2020). Evaluation of Two Chemiluminescent and Three ELISA Immunoassays for the Detection of SARS-CoV-2 IgG Antibodies: Implications for Disease Diagnosis and Patients\u2019 Management. Front. Immunol., 11.","DOI":"10.3389\/fimmu.2020.609242"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"104690","DOI":"10.1016\/j.jcv.2020.104690","article-title":"Comparison of SARS-CoV-2 serological tests with different antigen targets","volume":"134","author":"Coste","year":"2021","journal-title":"J. Clin. Virol."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"e12614","DOI":"10.1016\/j.heliyon.2022.e12614","article-title":"Performance and correlation of ten commercial immunoassays for the detection of SARS-CoV-2 antibodies","volume":"8","author":"Lokida","year":"2022","journal-title":"Heliyon"},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Ju, J., Zhang, X., Li, L., Regmi, S., Yang, G., and Tang, S. (2022). Development of fluorescent lateral flow immunoassay for SARS-CoV-2-specific IgM and IgG based on aggregation-induced emission carbon dots. Front. Bioeng. Biotechnol., 10.","DOI":"10.3389\/fbioe.2022.1042926"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"100099","DOI":"10.1016\/j.xcrm.2020.100099","article-title":"Combined Point-of-Care Nucleic Acid and Antibody Testing for SARS-CoV-2 following Emergence of D614G Spike Variant","volume":"1","author":"Mlcochova","year":"2020","journal-title":"Cell Rep. Med."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"155","DOI":"10.1186\/s13643-021-01689-3","article-title":"A systematic and meta-analysis review on the diagnostic accuracy of antibodies in the serological diagnosis of COVID-19","volume":"10","author":"Vengesai","year":"2021","journal-title":"Syst. Rev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"103729","DOI":"10.1016\/j.ebiom.2021.103729","article-title":"A point-of-care lateral flow assay for neutralising antibodies against SARS-CoV-2","volume":"74","author":"Fulford","year":"2021","journal-title":"EBioMedicine"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"2105611","DOI":"10.1080\/21645515.2022.2105611","article-title":"Correlation between anti-S IgG and neutralizing antibody titers against three live SARS-CoV-2 variants in BNT162b2 vaccine recipients","volume":"18","author":"Higashimoto","year":"2022","journal-title":"Hum. Vaccin. Immunother."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Takheaw, N., Liwsrisakun, C., Chaiwong, W., Laopajon, W., Pata, S., Inchai, J., Duangjit, P., Pothirat, C., Bumroongkit, C., and Deesomchok, A. (2022). Correlation Analysis of Anti-SARS-CoV-2 RBD IgG and Neutralizing Antibody against SARS-CoV-2 Omicron Variants after Vaccination. Diagnostics, 12.","DOI":"10.3390\/diagnostics12061315"},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Souiri, A., Lemriss, S., El Maliki, B., Falahi, H., El Fahime, E., and El Kabbaj, S. (2023). SARS-CoV-2-Neutralizing Antibody Response and Correlation of Two Serological Assays with Microneutralization. Vaccines, 11.","DOI":"10.3390\/vaccines11030590"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Schest, S., Langer, C., Stiegler, Y., Karnuth, B., Arends, J., Stiegler, H., Masetto, T., Peter, C., and Grimmler, M. (2023). Vaccine-induced SARS-CoV-2 antibody response: The comparability of S1-specific binding assays depends on epitope and isotype discrimination. Front. Immunol., 14.","DOI":"10.3389\/fimmu.2023.1257265"},{"key":"ref_46","doi-asserted-by":"crossref","unstructured":"Honning, A., Tomczyk, S., Hermes, J., Grossegesse, M., Hofmann, N., Michel, J., Neumann, M., Nitsche, A., Hoppe, B., and Eckmanns, T. (2024). Follow-up SARS-CoV-2 serological study of a health care worker cohort following COVID-19 booster vaccination. BMC Infect. Dis., 24.","DOI":"10.1186\/s12879-024-09338-5"},{"key":"ref_47","unstructured":"Angeloni, S., Cordes, R., Dunbar, S., Garcia, C., Gibson, G., Martin, C., and Stone, V. (2013). xMAP\u00ae Cookbook. A Collection of Methods and Protocols for Developing Multiplex Assays with xMAP Technology, Luminex xMAP Technology."},{"key":"ref_48","unstructured":"Diasorin (2025, May 19). xMAP\u00ae INTELLIFLEX Catalog. Available online: https:\/\/int.diasorin.com\/sites\/default\/files\/products-documentation-tool\/BR663101.xMAPCatalog.2024.EMEA_.1223WR.pdf."},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Rottmayer, K., Schwarze, M., Jassoy, C., Hoffmann, R., Loeffler-Wirth, H., and Lehmann, C. (2024). Potential of a Bead-Based Multiplex Assay for SARS-CoV-2 Antibody Detection. Biology, 13.","DOI":"10.3390\/biology13040273"},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"e0389822","DOI":"10.1128\/spectrum.03898-22","article-title":"Development, Validation, and Utilization of a Luminex-Based SARS-CoV-2 Multiplex Serology Assay","volume":"11","author":"Roy","year":"2023","journal-title":"Microbiol. Spectr."},{"key":"ref_51","unstructured":"MSD (2025, October 29). V-PLEX COVID-19 Serology Kits. Available online: https:\/\/www.mesoscale.com\/~\/media\/files\/product%20inserts\/v-plex%20covid-19%20serology%20assays%20insert.pdf."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Byrum, J.R., Waltari, E., Janson, O., Guo, S.M., Folkesson, J., Chhun, B.B., Vinden, J., Ivanov, I.E., Forst, M.L., and Li, H. (2023). MultiSero: An Open-Source Multiplex-ELISA Platform for Measuring Antibody Responses to Infection. Pathogens, 12.","DOI":"10.3390\/pathogens12050671"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"406","DOI":"10.1002\/prca.201400130","article-title":"ELISA in the multiplex era: Potentials and pitfalls","volume":"9","author":"Tighe","year":"2015","journal-title":"Proteom. Clin. Appl."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"2348","DOI":"10.1056\/NEJMoa2105290","article-title":"Phase 3 Safety and Efficacy of AZD1222 (ChAdOx1 nCoV-19) COVID-19 Vaccine","volume":"385","author":"Falsey","year":"2021","journal-title":"N. Engl. J. Med."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1126\/science.abm3425","article-title":"Immune correlates analysis of the mRNA-1273 COVID-19 vaccine efficacy clinical trial","volume":"375","author":"Gilbert","year":"2022","journal-title":"Science"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"e146316","DOI":"10.1172\/jci.insight.146316","article-title":"A majority of uninfected adults show preexisting antibody reactivity against SARS-CoV-2","volume":"6","author":"Majdoubi","year":"2021","journal-title":"JCI Insight"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"322","DOI":"10.4049\/immunohorizons.2100011","article-title":"One-Stop Serum Assay Identifies COVID-19 Disease Severity and Vaccination Responses","volume":"5","author":"Haddad","year":"2021","journal-title":"Immunohorizons"},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"eade2798","DOI":"10.1126\/sciimmunol.ade2798","article-title":"Class switch toward noninflammatory, spike-specific IgG4 antibodies after repeated SARS-CoV-2 mRNA vaccination","volume":"8","author":"Irrgang","year":"2023","journal-title":"Sci. Immunol."},{"key":"ref_59","doi-asserted-by":"crossref","first-page":"106473","DOI":"10.1016\/j.jinf.2025.106473","article-title":"Post-vaccination IgG4 and IgG2 class switch associates with increased risk of SARS-CoV-2 infections","volume":"90","author":"Vidal","year":"2025","journal-title":"J. Infect."},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"eads1482","DOI":"10.1126\/sciadv.ads1482","article-title":"Increased SARS-CoV-2 IgG4 has variable consequences dependent upon Fc function, Fc receptor polymorphism, and viral variant","volume":"11","author":"Aurelia","year":"2025","journal-title":"Sci. Adv."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"100329","DOI":"10.1016\/j.xcrm.2021.100329","article-title":"Serological analysis reveals an imbalanced IgG subclass composition associated with COVID-19 disease severity","volume":"2","author":"Yates","year":"2021","journal-title":"Cell Rep. Med."},{"key":"ref_62","doi-asserted-by":"crossref","first-page":"107990","DOI":"10.1016\/j.ijid.2025.107990","article-title":"Class switch toward IgG2 and IgG4 is more pronounced in BNT162b2 compared to mRNA-1273 COVID-19 vaccinees","volume":"159","author":"Siebner","year":"2025","journal-title":"Int. J. Infect. Dis."},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"3808","DOI":"10.1200\/JCO.21.02986","article-title":"Antibody Response to COVID-19 mRNA Vaccine in Patients With Lung Cancer After Primary Immunization and Booster: Reactivity to the SARS-CoV-2 WT Virus and Omicron Variant","volume":"40","author":"Valanparambil","year":"2022","journal-title":"J. Clin. Oncol."},{"key":"ref_64","doi-asserted-by":"crossref","unstructured":"Horbach, I.S., de Souza Azevedo, A., Schwarcz, W.D., Alves, N.D.S., de Moura Dias, B., Setatino, B.P., da Cruz Moura, L., de Souza, A.F., Denani, C.B., and da Silva, S.A. (2024). Plaque Reduction Neutralization Test (PRNT) Accuracy in Evaluating Humoral Immune Response to SARS-CoV-2. Diseases, 12.","DOI":"10.3390\/diseases12010029"},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"4059","DOI":"10.1038\/s41467-020-17892-0","article-title":"A high-throughput neutralizing antibody assay for COVID-19 diagnosis and vaccine evaluation","volume":"11","author":"Muruato","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_66","doi-asserted-by":"crossref","first-page":"5214","DOI":"10.1038\/s41467-020-19055-7","article-title":"A nanoluciferase SARS-CoV-2 for rapid neutralization testing and screening of anti-infective drugs for COVID-19","volume":"11","author":"Xie","year":"2020","journal-title":"Nat. Commun."},{"key":"ref_67","doi-asserted-by":"crossref","first-page":"e0037622","DOI":"10.1128\/jcm.00376-22","article-title":"Development of a Rapid Live SARS-CoV-2 Neutralization Assay Based on a qPCR Readout","volume":"60","author":"Lichtenegger","year":"2022","journal-title":"J. Clin. Microbiol."},{"key":"ref_68","doi-asserted-by":"crossref","first-page":"2105","DOI":"10.1080\/22221751.2020.1815589","article-title":"Robust neutralization assay based on SARS-CoV-2 S-protein-bearing vesicular stomatitis virus (VSV) pseudovirus and ACE2-overexpressing BHK21 cells","volume":"9","author":"Xiong","year":"2020","journal-title":"Emerg. Microbes Infect."},{"key":"ref_69","doi-asserted-by":"crossref","first-page":"680","DOI":"10.1080\/22221751.2020.1743767","article-title":"Establishment and validation of a pseudovirus neutralization assay for SARS-CoV-2","volume":"9","author":"Nie","year":"2020","journal-title":"Emerg. Microbes Infect."},{"key":"ref_70","doi-asserted-by":"crossref","first-page":"23921","DOI":"10.1038\/s41598-021-03154-6","article-title":"Calibration of two validated SARS-CoV-2 pseudovirus neutralization assays for COVID-19 vaccine evaluation","volume":"11","author":"Huang","year":"2021","journal-title":"Sci. Rep."},{"key":"ref_71","doi-asserted-by":"crossref","first-page":"100856","DOI":"10.1016\/j.crmeth.2024.100856","article-title":"A quadri-fluorescence SARS-CoV-2 pseudovirus system for efficient antigenic characterization of multiple circulating variants","volume":"4","author":"Chen","year":"2024","journal-title":"Cell Rep. Methods"},{"key":"ref_72","doi-asserted-by":"crossref","first-page":"1478","DOI":"10.3201\/eid2607.200841","article-title":"Severe Acute Respiratory Syndrome Coronavirus 2-Specific Antibody Responses in Coronavirus Disease Patients","volume":"26","author":"Okba","year":"2020","journal-title":"Emerg. Infect. Dis."},{"key":"ref_73","doi-asserted-by":"crossref","first-page":"e108","DOI":"10.1002\/cpmc.108","article-title":"An In Vitro Microneutralization Assay for SARS-CoV-2 Serology and Drug Screening","volume":"58","author":"Amanat","year":"2020","journal-title":"Curr. Protoc. Microbiol."},{"key":"ref_74","doi-asserted-by":"crossref","unstructured":"Liu, K.T., Han, Y.J., Wu, G.H., Huang, K.A., and Huang, P.N. (2022). Overview of Neutralization Assays and International Standard for Detecting SARS-CoV-2 Neutralizing Antibody. Viruses, 14.","DOI":"10.3390\/v14071560"},{"key":"ref_75","doi-asserted-by":"crossref","first-page":"e116","DOI":"10.1002\/cpim.116","article-title":"Development of a Rapid Focus Reduction Neutralization Test Assay for Measuring SARS-CoV-2 Neutralizing Antibodies","volume":"131","author":"Vanderheiden","year":"2020","journal-title":"Curr. Protoc. Immunol."},{"key":"ref_76","doi-asserted-by":"crossref","first-page":"3114","DOI":"10.1038\/s41596-021-00536-y","article-title":"Quantification of SARS-CoV-2 neutralizing antibody by wild-type plaque reduction neutralization, microneutralization and pseudotyped virus neutralization assays","volume":"16","author":"Bewley","year":"2021","journal-title":"Nat. Protoc."},{"key":"ref_77","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1208\/s12248-023-00830-5","article-title":"Neutralizing Antibody Validation Testing and Reporting Harmonization","volume":"25","author":"Myler","year":"2023","journal-title":"AAPS J."},{"key":"ref_78","doi-asserted-by":"crossref","first-page":"1979","DOI":"10.1016\/S0140-6736(20)32466-1","article-title":"Safety and immunogenicity of ChAdOx1 nCoV-19 vaccine administered in a prime-boost regimen in young and old adults (COV002): A single-blind, randomised, controlled, phase 2\/3 trial","volume":"396","author":"Ramasamy","year":"2021","journal-title":"Lancet"},{"key":"ref_79","doi-asserted-by":"crossref","first-page":"3602","DOI":"10.1038\/s41467-022-30681-1","article-title":"Neutralization of Omicron BA.1, BA.2, and BA.3 SARS-CoV-2 by 3 doses of BNT162b2 vaccine","volume":"13","author":"Kurhade","year":"2022","journal-title":"Nat. Commun."},{"key":"ref_80","doi-asserted-by":"crossref","first-page":"589","DOI":"10.1038\/s41586-020-2639-4","article-title":"Phase I\/II study of COVID-19 RNA vaccine BNT162b1 in adults","volume":"586","author":"Mulligan","year":"2020","journal-title":"Nature"},{"key":"ref_81","doi-asserted-by":"crossref","unstructured":"Frische, A., Brooks, P.T., Gybel-Brask, M., S\u00e6kmose, S.G., Jensen, B.A., Mikkelsen, S., Bruun, M.T., Boding, L., Strandh, C.P., and J\u00f8rgensen, C.S. (2022). Optimization and evaluation of a live virus SARS-CoV-2 neutralization assay. PLoS ONE, 17.","DOI":"10.1371\/journal.pone.0272298"},{"key":"ref_82","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1080\/14760584.2023.2299380","article-title":"Pseudoviruses, a safer toolbox for vaccine development against enveloped viruses","volume":"23","author":"Thimmiraju","year":"2024","journal-title":"Expert. Rev. Vaccines"},{"key":"ref_83","doi-asserted-by":"crossref","first-page":"e1963","DOI":"10.1002\/rmv.1963","article-title":"Current status on the development of pseudoviruses for enveloped viruses","volume":"28","author":"Li","year":"2018","journal-title":"Rev. Med. Virol."},{"key":"ref_84","doi-asserted-by":"crossref","first-page":"8463","DOI":"10.1128\/JVI.72.11.8463-8471.1998","article-title":"A third-generation lentivirus vector with a conditional packaging system","volume":"72","author":"Dull","year":"1998","journal-title":"J. Virol."},{"key":"ref_85","doi-asserted-by":"crossref","unstructured":"Crawford, K.H.D., Eguia, R., Dingens, A.S., Loes, A.N., Malone, K.D., Wolf, C.R., Chu, H.Y., Tortorici, M.A., Veesler, D., and Murphy, M. (2020). Protocol and Reagents for Pseudotyping Lentiviral Particles with SARS-CoV-2 Spike Protein for Neutralization Assays. Viruses, 12.","DOI":"10.1101\/2020.04.20.051219"},{"key":"ref_86","doi-asserted-by":"crossref","first-page":"e20201181","DOI":"10.1084\/jem.20201181","article-title":"Measuring SARS-CoV-2 neutralizing antibody activity using pseudotyped and chimeric viruses","volume":"217","author":"Schmidt","year":"2020","journal-title":"J. Exp. Med."},{"key":"ref_87","doi-asserted-by":"crossref","first-page":"365","DOI":"10.1016\/j.jviromet.2010.08.006","article-title":"Generation of VSV pseudotypes using recombinant \u0394G-VSV for studies on virus entry, identification of entry inhibitors, and immune responses to vaccines","volume":"169","author":"Whitt","year":"2010","journal-title":"J. Virol. Methods"},{"key":"ref_88","doi-asserted-by":"crossref","first-page":"331","DOI":"10.1038\/s41467-022-35768-3","article-title":"Immune correlates analysis of the PREVENT-19 COVID-19 vaccine efficacy clinical trial","volume":"14","author":"Fong","year":"2023","journal-title":"Nat. Commun."},{"key":"ref_89","doi-asserted-by":"crossref","first-page":"572","DOI":"10.1038\/s41586-021-03653-6","article-title":"BNT162b2 vaccine induces neutralizing antibodies and poly-specific T cells in humans","volume":"595","author":"Sahin","year":"2021","journal-title":"Nature"},{"key":"ref_90","doi-asserted-by":"crossref","first-page":"2190690","DOI":"10.1080\/21645515.2023.2190690","article-title":"Interim analysis of a phase 1 randomized clinical trial on the safety and immunogenicity of the mRNA-1283 SARS-CoV-2 vaccine in adults","volume":"19","author":"Yassini","year":"2023","journal-title":"Hum. Vaccin. Immunother."},{"key":"ref_91","doi-asserted-by":"crossref","unstructured":"Neerukonda, S.N., Vassell, R., Herrup, R., Liu, S., Wang, T., Takeda, K., Yang, Y., Lin, T.L., Wang, W., and Weiss, C.D. (2021). Establishment of a well-characterized SARS-CoV-2 lentiviral pseudovirus neutralization assay using 293T cells with stable expression of ACE2 and TMPRSS2. PLoS ONE, 16.","DOI":"10.1101\/2020.12.26.424442"},{"key":"ref_92","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1111\/j.1538-7836.2006.01749.x","article-title":"Lentivirus degradation and DC-SIGN expression by human platelets and megakaryocytes","volume":"4","author":"Boukour","year":"2006","journal-title":"J. Thromb. Haemost."},{"key":"ref_93","doi-asserted-by":"crossref","first-page":"689","DOI":"10.1126\/science.1181766","article-title":"Cryo-EM model of the bullet-shaped vesicular stomatitis virus","volume":"327","author":"Ge","year":"2010","journal-title":"Science"},{"key":"ref_94","doi-asserted-by":"crossref","first-page":"e01062-20","DOI":"10.1128\/JVI.01062-20","article-title":"Optimized Pseudotyping Conditions for the SARS-COV-2 Spike Glycoprotein","volume":"94","author":"Johnson","year":"2020","journal-title":"J. Virol."},{"key":"ref_95","doi-asserted-by":"crossref","first-page":"e0096621","DOI":"10.1128\/JVI.00966-21","article-title":"Cytoplasmic Tail Truncation of SARS-CoV-2 Spike Protein Enhances Titer of Pseudotyped Vectors but Masks the Effect of the D614G Mutation","volume":"95","author":"Chen","year":"2021","journal-title":"J. Virol."},{"key":"ref_96","doi-asserted-by":"crossref","unstructured":"Cai, Z., Kalkeri, R., Zhu, M., Cloney-Clark, S., Haner, B., Wang, M., Osman, B., Dent, D., Feng, S.L., and Longacre, Z. (2024). A Pseudovirus-Based Neutralization Assay for SARS-CoV-2 Variants: A Rapid, Cost-Effective, BSL-2-Based High-Throughput Assay Useful for Vaccine Immunogenicity Evaluation. Microorganisms, 12.","DOI":"10.3390\/microorganisms12030501"},{"key":"ref_97","doi-asserted-by":"crossref","first-page":"e2261566","DOI":"10.1080\/22221751.2023.2261566","article-title":"Development of an automated, high-throughput SARS-CoV-2 neutralization assay based on a pseudotyped virus using a vesicular stomatitis virus (VSV) vector","volume":"12","author":"Liang","year":"2023","journal-title":"Emerg. Microbes Infect."},{"key":"ref_98","doi-asserted-by":"crossref","first-page":"475","DOI":"10.1016\/j.chom.2020.06.021","article-title":"Neutralizing Antibody and Soluble ACE2 Inhibition of a Replication-Competent VSV-SARS-CoV-2 and a Clinical Isolate of SARS-CoV-2","volume":"28","author":"Case","year":"2020","journal-title":"Cell Host Microbe"},{"key":"ref_99","first-page":"pgac045","article-title":"Quantitation of SARS-CoV-2 neutralizing antibodies with a virus-free, authentic test","volume":"1","author":"Roessler","year":"2022","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_100","doi-asserted-by":"crossref","first-page":"e615","DOI":"10.1002\/mco2.615","article-title":"Optimization and validation of a virus-like particle pseudotyped virus neutralization assay for SARS-CoV-2","volume":"5","author":"Liu","year":"2024","journal-title":"MedComm"},{"key":"ref_101","unstructured":"Diazyme Laboratories (2022). Diazyme SARS-CoV-2 Neutralizing Antibody CLIA Kit Instruction For Use, Diazyme Laboratories, Inc."},{"key":"ref_102","doi-asserted-by":"crossref","first-page":"eabi8452","DOI":"10.1126\/scitranslmed.abi8452","article-title":"A high-throughput cell- and virus-free assay shows reduced neutralization of SARS-CoV-2 variants by COVID-19 convalescent plasma","volume":"13","author":"Fenwick","year":"2021","journal-title":"Sci. Transl. Med."},{"key":"ref_103","doi-asserted-by":"crossref","unstructured":"Patil, R., Palkar, S., Mishra, A., Patil, R., and Arankalle, V. (2023). Variable neutralizing antibody responses to 10 SARS-CoV-2 variants in natural infection with wild-type (B.1) virus, Kappa (B.1.617.1), and Delta (B.1.617.2) variants and COVISHIELD vaccine immunization in India: Utility of the MSD platform. Front. Immunol., 14.","DOI":"10.3389\/fimmu.2023.1181991"},{"key":"ref_104","doi-asserted-by":"crossref","unstructured":"Sholukh, A.M., Fiore-Gartland, A., Ford, E.S., Hou, Y., Tse, L.V., Lempp, F.A., Kaiser, H., Saint Germain, R., Bossard, E., and Kee, J.J. (2020). Evaluation of SARS-CoV-2 neutralization assays for antibody monitoring in natural infection and vaccine trials. medRxiv.","DOI":"10.1101\/2020.12.07.20245431"},{"key":"ref_105","doi-asserted-by":"crossref","first-page":"3125","DOI":"10.2147\/IJN.S408921","article-title":"Development of an Effective Neutralizing Antibody Assay for SARS-CoV-2 Diagnosis","volume":"18","author":"Liu","year":"2023","journal-title":"Int. J. Nanomed."},{"key":"ref_106","doi-asserted-by":"crossref","first-page":"5407","DOI":"10.1021\/acs.analchem.3c05144","article-title":"Overlaid Lateral Flow Immunoassay for the Simultaneous Detection of Two Variant-Specific SARS-CoV-2 Neutralizing Antibodies","volume":"96","author":"Deenin","year":"2024","journal-title":"Anal. Chem."},{"key":"ref_107","unstructured":"Bentley, E. (2022). Establishment of the 2nd WHO International Standard for Anti-SARS-CoV-2 Immunoglobulin and Reference Panel for Antibodies to SARS-CoV-2 Variants of Concern, World Health Organization."},{"key":"ref_108","unstructured":"U.S. Food & Drug Administration (2026, January 05). COVID-19 Vaccines (2025\u20132026 Formula) for Use in the United States Beginning in Fall 2025, Available online: https:\/\/www.fda.gov\/vaccines-blood-biologics\/industry-biologics\/covid-19-vaccines-2025-2026-formula-use-united-states-beginning-fall-2025."},{"key":"ref_109","doi-asserted-by":"crossref","first-page":"e0099522","DOI":"10.1128\/jcm.00995-22","article-title":"Selection, Characterization, Calibration, and Distribution of the U.S. Serology Standard for Anti-SARS-CoV-2 Antibody Detection","volume":"60","author":"Kemp","year":"2022","journal-title":"J. Clin. Microbiol."},{"key":"ref_110","doi-asserted-by":"crossref","first-page":"609","DOI":"10.1016\/j.it.2024.06.003","article-title":"Protective non-neutralizing SARS-CoV-2 monoclonal antibodies","volume":"45","author":"Izadi","year":"2024","journal-title":"Trends Immunol."},{"key":"ref_111","doi-asserted-by":"crossref","first-page":"3385","DOI":"10.1093\/jimmun\/vkaf123","article-title":"Non-neutralizing antibodies against SARS-CoV-2 nucleocapsid protein mediate variant transcendent antibody-dependent cellular cytotoxicity","volume":"214","author":"Osuagwu","year":"2025","journal-title":"J. Immunol."},{"key":"ref_112","doi-asserted-by":"crossref","first-page":"e0131522","DOI":"10.1128\/spectrum.01315-22","article-title":"Correlation of SARS-CoV-2 Viral Neutralizing Antibody Titers with Anti-Spike Antibodies and ACE-2 Inhibition among Vaccinated Individuals","volume":"10","author":"Grunau","year":"2022","journal-title":"Microbiol. Spectr."},{"key":"ref_113","doi-asserted-by":"crossref","first-page":"54","DOI":"10.1016\/j.clinbiochem.2021.08.006","article-title":"Multiplex assessment of SARS-CoV-2 antibodies improves assay sensitivity and correlation with neutralizing antibodies","volume":"97","author":"Cook","year":"2021","journal-title":"Clin. Biochem."},{"key":"ref_114","doi-asserted-by":"crossref","unstructured":"Lerdsamran, H., Anusorntanawat, R., Sangsiriwut, K., Sawadpongpan, S., Prasertsopon, J., Thinpan, N., Intalapaporn, P., Techasuwanna, R., Okada, P., and Puthavathana, P. (2024). Higher correlation between neutralizing antibodies and surrogate neutralizing or binding antibodies in COVID-19 patients than vaccine recipients. PLoS ONE, 19.","DOI":"10.1371\/journal.pone.0298033"},{"key":"ref_115","doi-asserted-by":"crossref","unstructured":"Fu, J., Shen, X., Anderson, M., Stec, M., Petratos, T., Cloherty, G., Montefiori, D.C., Landay, A., and Moy, J.N. (2022). Correlation of Binding and Neutralizing Antibodies against SARS-CoV-2 Omicron Variant in Infection-Naive and Convalescent BNT162b2 Recipients. Vaccines, 10.","DOI":"10.3390\/vaccines10111904"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/5\/395\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,30]],"date-time":"2026-04-30T04:39:33Z","timestamp":1777523973000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/5\/395"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,28]]},"references-count":115,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["vaccines14050395"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14050395","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,28]]}}}