Kinetics of Anti-Sars-Cov-2 Igg Antibodies Post-Covid-19 -Vaccination

ABSTRACT

Intro During the pandemic of COVD-19, several vaccines have been developed and are currently used worldwide. However, head-to-head studies comparing various vaccines are limited. Therefore, This single-center, prospective, realworld study. head-to-head study of compared the effectiveness of BNT162b2 (Pfizer BioNTech), mRNA-1273 (Moderna) ChAdOx1-S (Astra Zeneca) vaccines. The kinetics of SARS-CoV2 spike antibodies were monitored post-vaccination and following two booster doses in COVID-19 naive and previously infected adults. Method(s) The primary outcome was the emergence of virologically positive COVID-19 cases after vaccine completion. The secondary outcome was the occurrence of postvaccination COVID-19-related hospitalizations. The titers of anti-SARS-CoV-2 IgG antibodies against the S1 subunit of the virus's spike protein were measured after the first and second doses of the three vaccines and the booster doses. Finding(s) The current study enrolled and followed 1550 participants who received ChAdOx1-S or BNT162b2, or mRNA-1273, and 1550 non-vaccinated subjects between March 2021 and February 2022. After completing two vaccine doses, the effectiveness in preventing COVID-19 cases was 89.2%, 95.5%, and 94.6% for ChAdOx1-S or BNT162b2, or mRNA-1273, respectively. Four COVID-19-related hospitalizations (0.26%) were reported in the vaccinated versus 648 (41.81%) non-vaccinated participants (P<0.0001). Following the Pfizer booster dose, no COVID-19-positive cases or hospitalizations were reported. In the three vaccines, SARS-CoV2 antibody titers increased gradually after the first dose, peaked 3-4 weeks after the second dose, then declined after 28-32 weeks. Enhanced antibody response was observed after the booster dose and was maintained until the end of follow-up. Comorbidities were associated with lower antibody titers, particularly diabetes, autoimmune diseases, and advanced renal diseases. Conclusion(s) The study showed that the three COVID-10 vaccines effectively reduced the risk of virologically confirmed COVID-19 disease and prevented severe illness and hospitalizations in COVID-19 naiive and previously infected. Booster doses enhance the SARS-CoV2 antibody response and decrease the incidence of virologically proven severe COVID-19.Copyright © 2023