World Health Organization OKs Large-Scale Trial of AIDS Vaccine

The World Health Organization on Friday gave the go-ahead to large-scale trials of a vaccine to try to prevent infection with the virus that causes AIDS.

A meeting of experts said small-scale trials on people in the United States and Europe had shown that the vaccine was safe and had some impact on improving the immune system.

The U.N. health agency said, however, that too little was known about the vaccine to predict its effectiveness.

“From the information available so far, it is uncertain whether these vaccines will protect against infection in humans,” a WHO statement said.

WHO said that the complex trials are unlikely to start before 1996, and that it would take years for any results to show.

No sites have yet been chosen for the trials, which will involve several thousand people who do not carry the human immunodeficiency virus, which causes AIDS.

According to WHO figures, 17 million people have been infected with the virus since it first spread in the early 1980s. About 4 million have gone on to develop full-blown AIDS.