Date: Saturday, November 6, 2021
Session Title: B Cell Biology & Targets in Autoimmune & Inflammatory Disease Poster (0001–0010)
Session Type: Poster Session A
Session Time: 8:30AM-10:30AM
Background/Purpose: We compared humoral immune responses against SARS-CoV-2 to responses against spike-antigen after vaccination.
Methods: 800 health-care workers from University Medical Center Freiburg, Germany, were pursued for 9 months; 120/800 had COVID-19 infections. IgM, IgG and IgA responses against spike, nucleocapsid, ORF3A, ORF8 were determined by ELISA. Spike-specific and neutralizing antibody concentrations were quantified by functional assays. IgM, IgA, IgG and neutralizing antibody titers against Wuhan, B1.17 and B1.351 spike variants were measured after BNT162b2-vaccination.
Results: While acute infection induced robust and strong IgM, IgG and IgA response against viral spike and nucleocapsid proteins, antibody titers and neutralizing antibody concentrations decreased over time in ~50% of samples. IgM, IgG, IgA antibodies against ORF3A/ORF8 were also found in non-infected individuals. Furthermore, SARS-CoV2 infections induced strong humoral response against endemic coronaviruses HCoV-229E, -OC43, -NL63 and -HKU1. Spike-specific IgG+ memory B-cells were detected in ≤ 1/1000 B-cells also in convalescents with low virus-specific antibody titers indicating that SARS-CoV-2-directed memory B-cell formation may differ from humoral anti-viral responses. BNT162b2 prompted strong primary immune response against the Wuhan, B1.17 and B1.351 variants starting 1.5 weeks post vaccination. Inhibition of ACE2-binding and virus neutralization assays revealed higher neutralizing activity against Wuhan and B1.17 than against B1.351.
Conclusion: Humoral response against SARS-CoV-2 often subsides within nine months, whereas memory B-cells apparently uphold immune response. Cross-reactivity of anti-SARS-CoV-2 IgG with endemic coronaviruses could bias interpretation of POC tests. ORF3A and ORF8-antibodies are detectable in non-infected individuals and therefore not indicative of SARS-CoV-2 infections. Vaccination with BNT162b2 elicits higher anti-spike antibody titers than infection with SARS-CoV-2.
To cite this abstract in AMA style:FINZEL S, Peter N, Brand C, Fischer B, Keller B, Weigang S, Kochs G, Schwemmle M, Rieg S, Mathé P, Kern W, van der Hoek L, de la Rosa K, Jäck H, Warnatz K, Voll R, Eibel H. Humoral Immune Responses to SARS-CoV2 Infections and upon Vaccination Against SARS-CoV2 [abstract]. Arthritis Rheumatol. 2021; 73 (suppl 9). https://acrabstracts.org/abstract/humoral-immune-responses-to-sars-cov2-infections-and-upon-vaccination-against-sars-cov2/. Accessed June 2, 2023.
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ACR Meeting Abstracts - https://acrabstracts.org/abstract/humoral-immune-responses-to-sars-cov2-infections-and-upon-vaccination-against-sars-cov2/