A new drug called Tenofovir is being researched to see whether it can prevent HIV infection if it is taken before a person is exposed to the virus.

Dr Helene Gayle of the Gates Foundation told the plenary session of the14^th World AIDS conference that her organisation had recently awarded a grant to Family Health International to study the use of Tenofovir for pre-HIV exposure prophylaxis.

Tenofovir was chosen, said Gayle, because it had “high potential anti-retrovial activity” and it “had shown promising results in preventing HIV infection in animals exposed to HIV”.

Twenty one studies worldwide had also found that circumsized men had about half the risk of HIV infection as uncircumsized men, said Gayle. More studies were being conducted in Kenya and Uganda to examine this further, and particularly to see whether the behaviour associated with groups practicing circumcision played a part in this difference.

More research was also being done on the potential of diaphragms to reduce HIV infection, she added. The diaphragm, a vaginally inserted barrier contraceptive, covers the cervix which is more susceptible to the HI virus than vaginal tissue.

Dr Lawrence Corey, who is co-ordinating 27 vaccine trials worldwide, told the  plenary that the latest vaccine research was showing promise in stimulating the body’€™s immune cells’€™ (T cells) ability to fight the HI virus’€™s ability to replicate once it entered the body.

Gayle said these were some of the many tools being looked at to help prevent the spread of HIV globally but warned that, as “biomedical options” were unlikely to be “100% effective or universally available”, HIV prevention based on behaviour change was important.

She said it was possible to prevent two thirds of new infections worldwide ‘€“ or 28 million — using a package of 12 proven interventions identified by the Global HIV Prevention Working Group.

These include mass media campaigns, the promotion of voluntary HIV counselling and testing, school, youth and work programmes, condom promotion and prevention of mother-to-child HIV transmission programmes.

But Gayle and Indian activist Dr Suniti Solomon both emphasized that social factors affecting behaviour change also had to be addressed if the interventions were to work.

Gayle pointed out that people who had been sexually abused as children, were in violent relationships or were depressed were more likely to engage in risky sexual behaviour.

Solomon stressed that the worldwide increase in violence against women “reduces women’€™s ability to negotiate for safe sex”, as did illiteracy, poverty and economic dependence on men.

A recent Lancet study found HIV prevention to be 28 times cheaper than treatment. It costs about $11-17 to prevent sex workers from getting HIV, whereas it cost thousands to treat a person with HIV.

Thus the message coming strongly from Barcelona is that it is possible to  prevent HIV infection ‘€“ but only if enough resources are put into getting citizens to understand how they can stop the virus from entering their bodies.