Total serum IgG2 at baseline correlated positively with post-vaccine antibody scores (specific for pneumococcal serotypes 19A and 19F) and total serum IgA correlated positively with the Δ antibody score specific for hepatitis A. IgG2 is known for its anti-carbohydrate function and its association with an Fc receptor that may assist antigen persistence and presentation [84,85,86]. This evidence concerns the gene CD79A and hepatitis A virus infection.