A weak type of the AIDS virus may teach the body to protect itself against the more virulent and lethal form of the disease, researchers concluded after studying infections among prostitutes in Africa.
Dr. Phyllis Kanki, a scientist at the Harvard School of Public Health, said a nine-year study in Senegal showed that prostitutes infected with HIV-2, a weak type of the AIDS virus, had about a 70% less likelihood of acquiring HIV-1, the aggressive virus that causes most of the world's AIDS deaths.
"Our study suggests that maybe this related virus can tell us how we can make a vaccine that will create immunity against HIV-1," Kanki said in an interview.
HIV-2 can cause AIDS, but it is much less aggressive and much less virulent, she said.
In the study, to be published today in the journal Science, Kanki and her colleagues tracked the health of 756 prostitutes in Dakar, Senegal.
At the start, 138 women were infected with HIV-2 and 618 had no AIDS virus. After nine years, women infected with HIV-2 experienced less than a third of the HIV-1 infections compared with women who were infection-free at the start.