The effect of an immunosuppressive drug (azathioprine) on the latent infection of marmoset monkeys (Callithrix jacchus) with the oncogenic Herpesvirus saimiri.

Callithrix jacchus (CJ) marmoset monkeys can be latently infected with Herpesvirus saimiri (HVS). In order to determine whether this resistance to the oncogenic potential of HVS could be due to the immune surveillance, azathioprine, a known immunosuppressive drug, was given to 7 latently infected CJ marmosets. The animals died within 147 days probably from side effect caused by azathioprine, but no animal developed a tumor.