The observation that 14% of infants that received placebo were seropositive (IgA ≥20 AU/ml) prior to Dose 1 at 6 to 8 weeks of age and 38% by 28 days post-Dose 3 at approximately 18 weeks of age highlight the high rotavirus circulation and very early natural infection in this setting. The gene discussed is CD79A; the disease is infection.