IGHG3 and infection: Although broadly neutralizing antibodies were not induced, antibodies mediating Fc effector functions, including IgG3, were detected (4, 5, 7–9), and Fc functions such as antibody-dependent cellular cytotoxicity (ADCC) and complement deposition (ADC’D) inversely correlated with infection risk in a subset of vaccine recipients (3, 4, 9).