Immunogenicity and Durability of Antibody Responses to homologous and heterologous Vaccination with BNT162b2 and ChAdOx1 Vaccines for COVID-19 4665

Abstract Description During the COVID-19 pandemic, vaccines were developed based on various platform technologies and approved for emergency use. However, the comparative analysis of immunogenicity and the durability of vaccine-induced antibody responses depending on vaccine platforms or vaccination regimen have not been thoroughly examined for mRNA- or viral vector-based vaccines. Here we assessed spike-binding IgG levels and neutralizing capacity in 69 vaccinated individuals prime-boost immunized either by homologous (BNT162b2-BNT162b2 or ChAdOx1-ChAdOx1) vaccinations or heterologous (ChAdOx1-BNT162b2) vaccination for 6 months after the first vaccination. We found stronger induction and relatively rapid waning of antibody responses by the homologous vaccination of the mRNA vaccine, while weaker boost effect and stable maintenance of humoral immune responses in the viral vector vaccine group. Heterologous vaccination of ChAdOx1 and BNT162b2 resulted in the effective boost effect with the highest remaining antibody responses at 6 month post-primary vaccination. Topic Categories Vaccines and Immunotherapy (VAC)