CD4 and cytomegalovirus infection: Chronic CMV infection is associated with accelerated immuno-senescence, while having outspoken effects on senescence characteristics of the CD8+ cytotoxic T cell compartment, but with lesser effects on the CD4+ T helper cell population (Nikolich-Žugich and van Lier, 2017; Pawelec et al., 2009; Weltevrede et al., 2016).