The third inactivated vaccine booster dramatically enhanced SARS-CoV-2 antibody responses and did not influence the profile of prothrombotic antibody.

ABSTRACT

OBJECTIVE: The purpose of this study is to investigate the production of both SARS-CoV-2-specific antibodies and autoantibodies in serum following the third booster vaccination of the inactivated COVID-19 vaccine, and to study the effect of B cell subsets with CD27 and CD38 phenotypes in peripheral blood on antibody production. METHODS: Routine blood indexes, SARS-CoV-2 antibodies, platelet factor 4 and seven antiphospholipid antibodies were detected both before and 2 months after vaccination in the medical staff of the Zhongnan Hospital of Wuhan University. Peripheral blood B cell subtypes were detected prior to vaccination. RESULTS: Following immunization, the positive rate of anti-N-S1 IgG had increased from 24.8% to 91.3% and the average antibody concentration had increased by 11 times. The positive rate of NAb had increased from 24.8% to 91.3%, the average antibody concentration had increased by 12 times, and the primary increased anti-S1 IgG subtype was that of IgG1. Peripheral blood CD27+CD38+ B cells were positively correlated with antibody levels after vaccination and were a predictor of the antibody response. In addition, although some indicators showed slight absolute changes, the blood parameters and antiphospholipid antibodies of most volunteers were normal both before and after COVID-19 inactivated vaccine inoculation, and there was no statistical difference in abnormal rates either before or after inoculation. CONCLUSION: Antibodies in vivo were increased after vaccination with the inactivated vaccine, and IgG1 was the main subtype involved in response to the vaccine. Vaccination with the inactivated COVID-19 vaccine did not appear to affect thrombus-related autoantibodies. This article is protected by copyright. All rights reserved.