New Delhi

India is gearing up to test an AIDS vaccine targeted at its most prevalent strain of HIV for the first time. Safety trials of the vaccine are expected to begin this summer.

With 60,000 AIDS deaths confirmed so far and an estimated 4.5 million infections, India is second only to South Africa as the country hardest hit by AIDS. About 30 AIDS vaccine trials are already under way worldwide, and the first Indian trial may go some way to address concerns that India has been slow to respond to the epidemic.

“There have been no vaccine trials in India, and that's obviously a real worry,” says Seth Berkley, president of the International AIDS Vaccine Initiative (IAVI), a non-profit organization based in New York that is helping to organize the trial. “This is critically important, not only to India, but to the global effort to find a vaccine.”

The National AIDS Research Institute in Pune in western India is hoping to conduct the phase I trial, which is only intended to establish the safety of the vaccine, on 40 healthy volunteers in June.

India has in the past rejected plans to test imported vaccines as they did not target HIV subtype C, which is prevalent in India. Early vaccine candidates had been aimed instead at subtype B, which is prevalent in America and Europe.

Since 2000, the Indian government has been working with IAVI to develop and evaluate an India-specific AIDS vaccine. “This vaccine is now ready,” says Sekhar Chakrabarti, a scientist at the Indian Council for Medical Research who is involved in its development.

The vaccine to be tested is a live attenuated modified vaccinia Ankara virus containing the coding sequence of six HIV-1 subtype C genes isolated from an Indian strain. For the phase I trial, it will be produced by Therion Biologics, a biotech company based in Cambridge, Massachusetts.

Some AIDS groups have attacked the plan for the safety trial, which has yet to be approved by regulators. “We should abandon the plan, as there is no track record of success by previous candidate vaccines,” says Ishwar Gilada, secretary general of the Peoples Health Organization, an AIDS-prevention group in Mumbai. But Chakrabarti says that the vaccine candidate has a greater chance of success than older vaccines.