Animal studies of prophylaxis

Antiviral and immune-based intervention strategies have been evaluated in vivo in animal models based on infections with lentiviruses and other retroviruses to explore their effect on preventing or limiting de novo virus infection. Variables that can be experimentally manipulated to address specific questions relevant to postexposure prophylaxis (PEP) include timing of initiation of treatment, duration of treatment, dosing regimen, virus strain, and virus inoculum. Prevention of the establishment of infection by PEP has been documented under defined experimental conditions. However, in the event that early intervention is not effective in preventing infection, evidence supporting control of viral replication and disease progression mediated by early intervention has also been reported. Thus, PEP may have a significant impact in preventing or altering viral replication in vivo and disease course.