02/28/2002 "Natural AIDS immunity"

Natural AIDS immunity
- Ananova

Women remain HIV-free despite sex with infected partners.

Researchers think they have found why a dozen women have remained HIV-free despite having unprotected sex with an infected partner.

A team at University of Medicine and Dentistry of New Jersey believe the women have immune systems behaving as if they had been vaccinated against Aids.

Their study found that in most of the women, key immune cells worked in various ways to block the HIV virus from multiplying in their bodies and infecting them, information that could help create an Aids vaccine.

But the researchers and other Aids experts stress that the conclusions reached in the study shouldn't be interpreted to mean that sex without a condoms is safe for anyone.

"If people have unprotected sex with someone who is HIV-positive, they do so at their own peril," warned lead researcher Dr. Donald B. Louria, of the university's Department of Preventive Medicine and Community Health.

Louria noted that of the 18 women in the study, one was infected with HIV after nine years of frequent, unprotected sex - despite warnings from health workers against it.

Many researchers have been studying the tiny group of people who mysteriously have not become infected with the virus despite long-term, unprotected exposure.

Previous studies covered one or two immune factors, with similar results, but this study was the most comprehensive, said Susan Plaeger of the Division of Aids at the National Institute of Allergy and Infectious Diseases.

Dr. Timothy Babinchak, director of clinical research on infectious diseases at Thomas Jefferson University Hospital in Philadelphia, said the findings should encourage further study with more patients.

Besides helping in vaccine development, he said the information might help Aids doctors identify which people infected with the HIV virus are likely to progress to full-blown Aids most quickly.