Killing of various bacterial species including S. pneumoniae, Bordetella pertussis, Escherichia coli, Staphylococcus aureus and N. meningitidis was associated with IgA‐mediated intracellular killing via phagocytosis as highlighted in various vaccine studies (Figure 3).40, 41 Johnson et al. 41 observed an initial capsule‐specific serum pIgA response in both natural infection (1 month) and immunization (1–3 months). The gene discussed is CD79A; the disease is infection.