In line with this, infection without vaccination led to significantly increased IgG, but not IgG1, IgG2, IgG3, IgG4, IgA, or IGM, levels compared with (1) the non-infected group after two rounds of vaccination (p-value = 0.0052, Wilcoxon) but was not different compared with (2) infection with two vaccinations or with (3) three vaccinations in the absence of prior infection. The gene discussed is IGHG3; the disease is infection.