Vaccine Prevents AIDS Infection For The First Time Ever
For the first time ever, a vaccine for the AIDS virus has protected a significant number of people against infection.
The study was conducted in Thailand, where 16,402 volunteers were given six doses of the vaccine, or a placebo, in 2006. Three years later, 74 people who had received the placebo had acquired AIDS, while only 51 of those who got the vaccines did. The difference is small, but significant, experts say, suggesting that the vaccine is 31.2 percent effective.
Scientists are not completely sure why the vaccine worked. The most confusing aspect of the trial was that everyone who did become infected developed roughly the same amount of virus in their blood whether they got the vaccine or a placebo.
Whatever the vaccine does, he said, it does not seem to mimic the defenses of the rare individuals known to AIDS doctors as “long-term nonprogressors,” who do not get sick even though they are infected. They have low viral loads because they block reproduction in some way that is still mysterious.
