Given the demonstrated importance for both HSV-specific CD4+ and CD8+ T cells in clearance of virus from infected epithelium and in neural tissues in the mouse model of HSV infections [35-40], it is not surprising that HSV-2 cross-specific-T cell response elicited in CJ9-gD-immunized guinea pigs plays a critical role in limiting the replication of challenge virus during both primary infection and reactivation from latency. The gene discussed is CD4; the disease is infection.