CD4 and cytomegalovirus infection: Gamadia and colleagues determined the kinetics and characteristics of CMV-Tvis in the course of primary CMV infections in adult renal transplant recipients: in asymptomatic individuals the CMV-CD4+ Tvis response preceded the CMV-CD8+ Tvis response, whereas in symptomatic individuals the CMV-specific effector memory CD4+ T cell response was delayed and only detectable after antiviral therapy[6, 7].