Fig. 2: Distinct features of germinal center (GC) reactions after infection or vaccination.
From: B-cell and antibody responses to SARS-CoV-2: infection, vaccination, and hybrid immunity
Mild COVID-19 leads to extrafollicular (EF) and GC responses (left), whereas severe cases result in defective GC reactions and a shift toward pronounced EF responses (center). In contrast, mRNA vaccines elicit only minimal EF responses but persistent and pronounced GC reactions. Continuous B-cell maturation may cause consecutive class-switch recombination (CSR), which may explain the increased IgG4 levels after repeated mRNA vaccinations. Created with BioRender.com
