Mystery of AIDS-resistant monkeys revealed Scientists have found
a possible reason why some monkeys don't develop AIDS, despite
being infected by the equivalent to HIV. The findings could help
scientists better understand how HIV will affect different
individuals. Davenport says it has been known for about 5 to 10
years that some species of monkey do not get sick with AIDS,
despite being infected with simian immunodeficiency virus (SIV),
the monkey equivalent of HIV. "These animals appear to have a
very similar infection to HIV in humans but they don't get
sick," he says. He says it has been thought that these AIDS-
resistant species are natural hosts of SIV, which have coevolved
with the virus over a long time. "It is thought that they've met
some sort of equilibrium where the virus persists but without
making the host sick," says Davenport. By contrast, he says HIV
is thought to be only recently introduced into humans and
therefore not had a chance to coevolve. But, says Davenport,
scientists have been unabl