Following infection of mice on the cornea, virus is transported through axons to the trigeminal ganglia, where it can travel through axons back to body surfaces (shown here as blue staining cells in the hair follicles of the mouse whisker pad). VP16 is normally expressed late and packaged into virions, where it initiates viral gene expression in the infected cell. Once latency is established in neurons, the stochastic derepression of VP16 is required to initiate viral reactivation (see Thompson et al.,doi:10.1371/journal.ppat.1000352).

Image Credit: Nancy M. Sawtell, Cincinnati Children's Hospital Medical Center