Download This PaperAntibody Titers After a Third Dose of the SARS-CoV-2 BNT162b2 Vaccine in Immunocompromised Adults in Greece: Necessity of a Fourth Dose
16 Pages Posted: 19 May 2022
Date Written: May 12, 2022
Abstract
Real-world data suggests that protection against COVID-19 declines a few months after vaccination, particularly in the elderly and immunocompromised individuals. Our study aimed to analyze the humoral response induced by a third supplemental dose of BNT162b2 vaccine in a mixed cohort of immunocompromised individuals by determining anti-spike (anti-S) IgG antibody titers at baseline (pre-third vaccine dose) and 4 weeks after the third BNT162b2 additional dose.
Serum samples were obtained from a total group of 85 immunocompromised individuals (history of cancer: n=20, lymphoma: n=4, leukemia: n=3, transplant recipients: n=4, autoimmune disease: n=42, inflammatory disease: n=6, autoimmune diabetes type 1: n=6) all of whom had previously received a two-dose schedule of the vaccine. The average number of days between 2nd and 3rd dose was 139.6145 (±41.39071).
The overall IgG GMCs four weeks post vaccination were increased by more than 35 times (fold change = 35. 30, p<0.001). Fold changes were not significantly correlated with underlying condition, age, sex nor with days between 2nd and 3rd dose. Regarding reactogenicity, adverse events were not systematically recorded in our study. None of our study participants declared an ICSR submission, evidence confirming the absence of serious adverse events in this study.
Considering the predominance of omicron variants in the current period and the results of studies showing a decrease in the effectiveness of the 3rd dose after 10 weeks we highly recommend a fourth dose to this vulnerable population group.
Note:
Funding Information: None to declare.
Conflict of Interests: None to declare.
Ethical Approval: Written informed consent was obtained from all participants. Approval of the study protocol was obtainedby the ethics committee of the scientific council of the G. Gennimatas General Hospital (protocol number:1/13.1.2021), in accordance with the Declaration of Helsinki and the International Conference on Harmonization for Good Clinical Practice.
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