A weak spot in HIV spotted

February 15, 2007

Scientists have discovered a place on the outside part of AIDS virus that might be vulnerable to antibodies blocking the virus from infecting human cells. This could mean that an anti-HIV vaccine is possible in the future.

According to Peter Kwong, researcher at U.S National Institute of Health (NIH), this study is likely to contribute to finding HIV's "site of vulnerability" which could then be targeted with a vaccine that prevents the initial infection. The team of researchers have made atomic-level images of HIV and revealed the structure of a protein on the surface of the virus. This protein, called gp120, binds to an infection-fighting antibody and seems to be susceptible to attacks by this antibody called 'b12'. B12 can broadly neutralize the virus.

Researchers detailed the precise interaction as the virus tries to hook on to and infect cells sent to protect the body. They have captured an image of how the virus of human immunodeficiency attacks the human cells. Dr. Gary Nabel, an NIH vaccine expert and a co-author of the research, describes this first contact between the virus and the cells as a 'cautious handshake' which then becomes a 'hearty bear hug'. The virus grabs and infects the cells that are aimed at protecting the body.

Then the virus mutates quickly to fight the immune system's attacks as well as to counter the effect of antibodies that block the proteins with help of which HIV binds to a cell to infect it.

Scientists agree that a vaccine against AIDS would be an ideal way to stop the pandemic of this disease, but, with all importance of these findings, much work and studies are still needed. This implies that any vaccine against AIDS is probably still many years away.

The AIDS virus has killed more than 25 million people since it was first detected in 1981. Sub-Saharan Africa is the most severely affected by the epidemic. Approximately 40 million people live with HIV.

About a dozen potential vaccines are currently under development. Two products, one by Merck and one by Sanofi-Aventis, are now in advanced human trials.