Specific long-term changes in anti-SARS-CoV-2 IgG modifications and antibody functions in mRNA, adenovector, and protein subunit vaccines

Abstract

Different vaccine platforms were developed in 2019 and 2020 to provide immunization for protection against the SARS-CoV-2-caused disease COVID-19. The majority of vaccinated individuals will develop antibodies against SARS-CoV-2. The isotype (subclass) and Fc-glycosylation of IgG antibodies determine their affinity for secondary effector functions. For protein subunit vaccines in COVID-19, the IgG profile of the subclass and glycosylation are unknown. Therefore, we measured the IgG subclass and N-297 Fc glycosylation by ELISA and LC-MS/MS of anti-spike IgG from individuals vaccinated with the Taiwanese protein subunit vaccine Medigen, the mRNA vaccines (BNT, Moderna), and the adenovector Astrazeneca. Samples were taken after the first and second doses. For all vaccine types, the main IgG response was dominated by IgG1 and IgG3 as subclasses. For glycosylation, mRNA vaccines presented with an afucosylation after the first dose and a constant significant higher galactosylation and sialylation than non-mRNA vaccines.