IGHG3 and infection: PCA suggested that while patients with infection (infected/non-vaccinated; infection/vaccinated) clustered towards spike-associated (annotated as S∗) IgG3 as well as NC IgG, IgG1, IgG3, and IgA, patients with vaccination (non-infected/vaccinated: infected/vaccinated) clustered towards spike-associated IgG4.