CD4 and inborn error of immunity: Primary immunodeficiency (Carneiro-Sampaio and Coutinho, 2007); inverse correlation between viremia and virus-specific CD4 T cell response (Abendroth and Arvin, 2001; Malavige et al., 2008); SVV: (VZV infection model in rhesus macaques) prolonged viremia and higher viral titers in CD4 T cell depleted animals (Haberthur et al., 2011)