Herpes simplex virus type 1 (HSV-1) is a major human pathogen whose lifestyle is based on
a long-term dual interaction with the infected host. After initial infection and lytic replica-
tion at the body periphery, the virus enters the sensory neurons that innervate the epithelia
and establishes a lifelong latent infection in sensory ganglia. Periodic reactivation from
latency usually leads to the return of the virus to epithelial cells, where it produces secondary
lytic infections resulting in mild illness symptoms, such as cold sores.