In a first, an AIDS vaccine shows some success

Friday, September 25, 2009 at 3:21 AM Posted by Beijing News


Scientists and government leaders have already started mapping out how to try to improve the world's first successful AIDS vaccine, which protected one in three people from getting HIV in a large study in Thailand.

That's not good enough for immediate use, researchers say. Yet it is a watershed event in the 26 years since the AIDS virus was discovered. Recent setbacks led many scientists to think a successful vaccine would never be possible.

The World Health Organization and the U.N. agency UNAIDS said the results "instilled new hope" in the field, even though it likely will be years before a vaccine might be widely available.

"This is truly a great moment for world medicine," said Lt. Gen. Eric Schoomaker, the U.S. Army Surgeon General. The Army helped sponsor the study, the world's largest of an AIDS vaccine.

It was the first time scientists tried preventing HIV the same way they treat it — with a combination approach. The study used two vaccines that work in different ways, and that may be one reason the strategy worked, even though neither vaccine did when tested individually in earlier trials, scientists say.

The combo cut the risk of becoming infected with HIV by more than 31 percent in the study of more than 16,000 volunteers in Thailand, researchers announced Thursday in Bangkok.

That benefit is modest, yet "it's the first evidence that we could have a safe and effective preventive vaccine," said Col. Jerome Kim, an Army doctor who helped lead the study.

The outcome "gives me cautious optimism about the possibility of improving this result" and developing a more effective AIDS vaccine, said Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, which co-sponsored the study.

"It's an opening of a new gateway to a road that has brighter lights in it now and maybe some directions," he said. "We need to bring the best minds together and map the way forward."

That has already started. Dozens of researchers, vaccine makers and deep-pocket donors will meet next week in New York "to talk about where we go from here," said Dr. Alan Bernstein, executive director of the Global HIV Vaccine Enterprise, an alliance of government officials, AIDS scientists, funders such as the Bill & Melinda Gates Foundation, and the WHO. At the meeting will be researchers from the Thai trial, the Army and independent scientists.

Scientists around the world cheered the first taste of victory.

"Since the 1980s, we've been hearing we're going to have an AIDS vaccine in 10 years. For the first time in my lifetime, it feels as though we're actually getting on the right track," said Josh Ruxin, a Columbia University public health specialist who runs the Access Project, which helps health centers provide AIDS care in Rwanda.

The Thailand Ministry of Public Health conducted the study. The U.S. Army has long worked with the Thai government and others to develop and test vaccines and medicine to protect troops and the general public.

The study used strains of HIV common in Thailand. Whether such a vaccine would work against other strains in the U.S., Africa or elsewhere in the world is unknown, scientists stressed.

Even a marginally helpful vaccine could have a big impact. Every day, 7,500 people worldwide are newly infected with HIV; 2 million died of AIDS in 2007, UNAIDS estimates.

The study tested the two-vaccine combination in a "prime-boost" approach, in which the first one primes the immune system to attack HIV and the second one strengthens the response.

They are ALVAC, from Sanofi Pasteur, the vaccine division of French drugmaker Sanofi-Aventis; and AIDSVAX, originally developed by VaxGen Inc. and now held by Global Solutions for Infectious Diseases, a nonprofit founded by some former VaxGen employees.

Government AIDS info:





Anderson

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