Reduced Titers of Circulating Anti-SARS-CoV-2 Antibodies and Risk of COVID-19 Infection in Healthcare Workers during the Nine Months after Immunization with the BNT162b2 mRNA Vaccine

Vaccines

Fabbio Marcuccilli¹  Sandro Grelli¹  Marco Trabucco Aurilio²  Andrea Mazza³  Andrea Magrini³  Cristiana Ferrari³  Giuseppina Somma³  Luca Coppeta³  Umberto D’Ancona³  Stefano Rizza⁴  Antonio Pietroiusti⁵ 

[1] Department of Experimental Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;Department of Medicine and Health Sciences “V. Tiberio”, University of Molise, 86100 Campobasso, Italy;Department of Occupational Medicine, University of Rome Tor Vergata, 00133 Rome, Italy;Department of System Medicine, University of Rome Tor Vergata, Viale Oxford 81, 00133 Roma, Italy;Departmental Faculty of Medicine, University Unicamillus, 00131 Rome, Italy;

关键词: COVID-19;    SARS-CoV-2;    healthcare workers;    vaccine;    BNT162b2 mRNA vaccine;    anti-S-RBD antibodies;   

DOI  :  10.3390/vaccines10020141

来源: DOAJ

【 摘 要 】

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has had a tremendous impact on health services; hundreds of thousands of healthcare workers (HCWs) have died from coronavirus disease 2019 (COVID-19). The introduction of the BNT162b2 mRNA vaccine in Italy provided recipients with significant protection against COVID-19 within one to two weeks after the administration of the second of the two recommended doses. While the vaccine induces a robust T cell response, the protective role of factors and pathways other than those related to memory B cell responses to specific SARS-CoV-2 antigens remains unclear. This retrospective study aimed to evaluate the determinants of serological protection in a group of vaccinated HCWs (n = 793) by evaluating circulating levels of antiviral spike receptor-binding domain (S-RBD) antibodies during the nine-month period following vaccination. We found that 99.5% of the HCWs who received the two doses of the BNT162b2 vaccine developed protective antibodies that were maintained at detectable levels for as long as 250 days after the second dose of the vaccine. Multivariate analysis was performed on anti-S-RBD titers in a subgroup of participants (n = 173) that were evaluated twice during this period. The results of this analysis reveal that the antibody titer observed at the second time point was significantly related to the magnitude of the primary response, the time that had elapsed between the first and the second evaluation, and a previous history of SARS-CoV-2 infection. Of importance is the finding that despite waning antibody titers following vaccination, none of the study participants contracted severe COVID-19 during the observational period.

【 授权许可】

Unknown