Responses of infant rhesus monkeys to inoculation with Mason-Pfizer monkey virus materials.

Rhesus monkeys neonatally inoculated with Mason-Pfizer monkey virus (M-PMV) and virus-infected cells frequently developed viral and/or bacterial pneumonia and enteritis. Three characteristic hematologic patterns occurred among the inoculated animals and correlated well with the probability of survival. Postmortem examination of the animals revealed lymphadenopathy and thymic atrophy. M-PMV was present in lymph nodes, blood, brain, spleen, thymus, kidneys, and bone marrow. The disease induced in some animals had characteristics suggestive of a slow-virus-induced autoimmune response.