SHIV-KB9 infection of rhesus monkeys does not always cause disease-contribution of host immune factors and thymic output.

Simian-human immunodeficiency virus (SHIV) infection in the macaque is a model of HIV pathogenesis. KB9, a molecular clone of SHIV 89.6P, induced rapid and profound CD4(+) T cell loss in rhesus monkeys, followed by partial recovery in some.