Merck vaccine's failure shatters AIDS fighters' hopes

Hopes of finding a preventative tool to stop the spread of AIDS dealt a severe blow yesterday when an experimental HIV prevention vaccine failed to show protection against global pandemic, HIV/AIDS.

AIDS researchers on Friday (September 21) halted an HIV vaccine trial after determining that the Merck & Co., Inc.'s investigational HIV vaccine does not stop HIV infections.

In an announcement yesterday, Merck & Co Inc. said vaccination in a phase II clinical trial of its experimental HIV vaccine is being discontinued because the vaccine failed to work in a large international test.

The New Jersey-based drug maker said that it is ending enrollment and vaccination of volunteers in the trial, which was partly funded by the National Institute of Allergy and Infectious Diseases, part of the US National Institutes of Health.

The study, called STEP, was testing the efficacy of Merck & Company's experimental HIV vaccine known as V520. However, after a review of the trial data and results of an interim efficacy analysis of the study, it was determined by the independent Data Safety Monitoring Board for STEP that the vaccine failed to work, leading the developer to halt the study.

According to the officials at Merck, in the trial 24 of 741 volunteers, who were all free of HIV at the start, and got the vaccine as part of he experiment, later contracted HIV, the virus that causes AIDS, compared to 21 of 762 of the controlled group who received dummy shots.

"It's very disappointing news...A major effort to develop a vaccine for HIV really did not deliver on the promise," said Keith Gottesdiener, the head of Merck & Company's infectious disease and vaccine research group.

In the trial, which was an international phase II 'test of concept' trial in uninfected volunteers at high risk for acquiring HIV infection, the researchers included the volunteers most of whom were either homosexual men or female sex workers. They all were free of HIV at the beginning of the study, but were at high risk for getting the dreaded virus.

The failure has shattered hopes of all the AIDS preventing agencies and AIDS researchers who were desperately waiting for a preventative vaccine to treat the lethal infectious disease.

"This is a huge disappointment for all of us who have been involved in the search for an HIV vaccine," said Dr. Glenda Gray, principal investigator of the HVTN-sponsored Phambili trial. "HIV is ravaging our communities, and all the scientists, participants and communities involved in HIV vaccine studies have been affected by this epidemic. The scientific community must continue the race to find a vaccine to help secure an HIV free generation for the future."

HIV AIDS is spreading like forest fire worldwide AIDS, affecting nearly 40 million people globally. The infectious disease is now transmitted mostly during sex between a man and a woman.

Sub-Saharan Africa is the worst hit region by the HIV virus. The epidemic has engulfed more than 25 million sub-Saharan Africans since the incurable disease was first emerged in 1981. Around 40 million people now live with HIV infection, most in this hardest hit region.

Sub-Saharan Africa is still bearing the brunt of the AIDS epidemic, accounting for almost two-thirds of all HIV infections and 72 percent of global AIDS deaths, the UN AIDS agency leading the battle against the disease reported in November 2006. A huge and disproportionate 59 percent of sub-Saharans Africans with HIV are women, the report added.

China, the world’s most populous nation, is another Aids-hit region. In 1998, China's Ministry of Health had estimated that 10 million citizens of China could be living with HIV infection by 2010 unless a vigorous program of prevention and treatment of the dreaded virus was launched.

According to the new 2006 estimates released recently by the National AIDS Control Organization (NACO), supported by UNAIDS and WHO, national adult HIV prevalence in India is approximately 0.36%, which corresponds to an estimated 2 million to 3.1 million people living with HIV in the country.

There is no cure and the virus has killed 25 million people.