Scientists altered a single gene in the human version of the HIV virus in order to be able to infect a pig-tailed macaque monkey in their quest for a vaccine, Reuters reports:
"The genetically engineered virus, once injected into this monkey,
proliferates almost as much as it does in people, but the animal
ultimately suppresses it and the virus does not make it sick, they said. The strain is called simian-tropic HIV-1, or stHIV-1. Researchers hope to be able to test possible new AIDS drugs and vaccines in monkeys before trying them in people. There is a 'cousin' virus to HIV called SIV, or simian
immunodeficiency virus, that causes a disease similar to AIDS in
certain types of monkeys. But this monkey AIDS virus is not identical to the one that infects
people and is not a perfect substitute for testing drugs and vaccines
against HIV."
According to researcher Paul Bieniasz: "The slight problem is the monkeys don't go on to develop AIDS, they don't get sick." Because, reports Reuters, "after initially spreading in the monkey's body, the animal
succeeds in suppressing the virus — not completely clearing the virus
but driving it to very low levels."
