BRISBANE, Calif. -- An experimental vaccine tested in Thailand on about
2,500 drug users failed to protect them from becoming infected with HIV,
the vaccine's developer said.
The poor results were widely expected since VaxGen Inc. had said earlier
its vaccine didn't work in a larger North American study. Most AIDS
researchers agree vaccines are the only effective way to control the virus
that has killed 28 million people and infected 42 million more world-wide.
Two dozen other vaccines are being tested on 12,000 human volunteers, but
none has advanced as far as VaxGen's, and any successful candidate is
The vaccine, like most others being tested, doesn't contain the virus
itself and can't cause AIDS. The vaccine contains small, man-made genetic
bits of the virus, which scientists had hoped would provoke an immune
response strong enough to stop the virus from invading healthy cells.
In the study, 105 people given a placebo became infected with HIV, while
106 people vaccinated tested positive.