CD79A and infection: However, the potential relevance of such nuanced cell biology to outcomes of HIV vaccination can be found in observations that IgA can interfere with IgG-mediated ADCC (49, 50), and that IgA and ADCC were observed to have opposing relationships to risk of infection among vaccine recipients in the RV144 vaccine trial (3) whereas IgA has shown positive associations with protection in NHP vaccine models (46, 51).