Antibody responses post-booster COVID-19 vaccination: Insights from a single-center prospective cohort study

The study aimed to evaluate the effect of booster dose COVID-19 vaccines on prevention and humoral immune response in individuals with different vaccination schemes during the period BA.4 and BA.5 omicron sub-variants were globally dominant. The study included 146 individuals who preferred different vaccination schemes for booster doses. Anti-spike/RBD-IgG and neutralizing antibody levels were measured 28 days after the booster dose vaccination upon their consent. There is no significant difference between median antibody titers detected according to different vaccination schemes. SARS-CoV-2 neutralizing antibody inhibition percentages were detected significantly higher in serum samples before and after the last booster dose in 2 BNT162b2+1 +1 BNT162b2(99.42 %), 2 BNT162b2 + 2 BNT162b2(99.42 %), and 2 BNT162b2 + 3 BNT162b2(99.42 %) vaccination schemes (p p = 0.004, p = 0.044, p = 0.002,respectively). The study indicated that a booster vaccination dose provides a high level of protection against severe COVID-19 and death. We think that the variant- specific pancoronavirus vaccines will be necessary to protect against breakthrough infections.