YourThaiPlanet.com

A breakthrough in the world's largest and long-running HIV vaccine trial has given new hope in the battle against HIV/Aids. The results of the trial carried out in Thailand released yesterday show the vaccine has 31.2% efficacy in preventing HIV/Aids infections.

Although its effectiveness did not reach the 50% efficacy rate needed to apply for a vaccine licence, and the vaccine, tested on over 16,000 volunteers in Chon Buri and Rayong, cannot lower the level of virus in the blood, the result was considered a success. "The outcome represents a significant finding in HIV vaccine development because for the first time ever there is evidence that an Aids vaccine has preventive efficacy," Public Health Minister Witthaya Kaewparadai said.

"Although it is not high enough for use, the result will help future vaccine research and development." No previous vaccine trials have shown evidence of success against the virus. Jerome Kim, deputy director (science) of the US Military Research Programme, a partner in the project, hailed the results as a big step forward. "Although the results were modest, this is a very important scientific advance and gives us hope that a globally effective vaccine may be possible in the future," Col Kim said.

Researchers would have to determine why the vaccine worked, he said. Other project participants are the National Institute of Health and vaccine manufacturers Sanofi Pasteur and Global Solutions for Infectious Disease. The Thai Phase III HIV vaccine clinical trial began in October 2003. The so-called prime-boost test combines two vaccines - Alvac, which was created by France-based Sanofi Pasteur, and Aidsvax B/E, made by Global Solutions for Infectious Disease - to stimulate different immune response systems simultaneously.

Each volunteer was given a vaccine or a placebo over a one-year period and checked after at least three and a half years. It was controversial at the beginning mainly because of the previous failure of the Aidsvax component. Initially, the US$105 million (3.5 billion baht) project also faced a shortfall in volunteers.

Principal investigator Supachai Rerks-ngarm said infected volunteers developed roughly the same amount of virus in their blood whether they were given the vaccine or the placebo. At the start of the trial, none of the volunteers was infected. Half received the vaccine and the rest were given a placebo. Of the placebo recipients 74 of 8,198 became infected compared with 51 of 8,197 who received the vaccine. Two volunteers also died.

The vaccine was tested on volunteers - all HIV negative men and women aged from 18 to 30 - at average risk of infection starting in October 2003. Dr Supachai said it would take some time before a new Aids vaccine trial would start as scientists still had to analyse what particular response was effective in the clinical trial held in Thailand.

Scientists also have to report findings on volunteers and decide if a long-term project monitoring volunteers should be carried out since the efficacy did not match the researchers' goal. Mitchell Warren, executive director of the New York-based Global Advocacy for HIV Prevention, said talks about the effect of the vaccine were needed.

US ambassador to Thailand Eric John hoped the result would help Aids vaccine research. "This trial will be recognised. The conclusion has brought us one step closer to Aids vaccine development."

Content Courtesy of Bangkok Post

Thailand wins praise for AIDS vaccine trial

An experimental AIDS vaccine that appears to be the first to protect people was mired for years in controversy, and credit for its success must go to Thailand where the trial was conducted, experts said.

The trial was criticised five years ago by 22 prominent U.S. scientists who doubted it would have any effect. Washington was accused of wasting more than a $100 million by funding it.

But Thai health authorities and their U.S. partners at the National Institutes of Health and the Walter Reed Army Institute of Research pressed on with the trial involving 16,000 volunteers in a country at the forefront of the battle against HIV.

"It was a tough decision. I am glad we made it," said Dr. Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, who defied the criticism and continued the trial.

The trial vaccine was made using two failed products Sanofi-Pasteur's ALVAC canary pox/HIV vaccine and AIDSVAX, made by a San Francisco company called VaxGen and now owned by the non-profit Global Solutions for Infectious Disease.

Donald Burke, dean of the University of Pittsburgh's Graduate School of Public Health, said the trial was controversial from the start and had been dismissed by prominent U.S. scientists because of the failure of previous vaccine tests.

"But given the importance of the AIDS epidemic, the decision was made to go forward regardless of these criticisms. It was a difficult choice, but a courageous choice," said Burke, who was head of AIDS research at Walter Reed before retiring in 1997.

Burke isolated the AIDS virus taken from a young HIV-infected Thai soldier in 1989 after Thai army doctors discovered an HIV outbreak among young recruits in Chiang Mai in northern Thailand. That virus sample went on to become one of the seed viruses in the experimental vaccine, Burke said.

"To their credit the Thais did a remarkable job on this," Dr. Eric Schoomaker, the Surgeon General of the U.S. Army, told reporters. "They did remarkable job of recruiting volunteers and conducting this trial almost flawlessly."

The $105 million trial was sponsored and paid for by the U.S. government and results showed it cut the risk of infection by 31.2 per cent among 16,402 volunteers over three years.

Those results mark a triumph for Thailand, a country of 67 million people where a booming sex industry had stoked fears of a major epidemic. Local authorities battled hard against a disease that threatened to spiral out of control some 20 years ago.

Experts had predicted that 4 million people would be infected by 2000 if nothing was done to slow the spread of HIV. But a massive government-led Aids education and prevention campaign in the early 1990s had an enormous effect.

HIV prevalence among injecting drug users in Thailand was as high as 30-50 per cent in 1991, and 33.2 per cent among female sex workers in 1994, according to UNAIDS. The number of infections has since been reduced to 20,000 annually from 140,000 in 1991. Billboards and airwaves were bombarded with safe sex messages while health workers promoted condom use in the country's notorious sex trade.

Leading the campaign was "Mr Condom," family planner-turned Public Health Minister, Meechai Viravaidya. Health check-ups were made available to sex workers for free. Men were discouraged from visiting prostitutes and condom usage in Bangkok's brothels rose from 15 per cent in the early 1990s to 98 per cent by 2000.

Infection rates fell and the exercise remains widely cited as a model in disease prevention among health experts -- although numbers have shown signs of creeping up in the last few years among some high risk groups, such as gay and bisexual men.

Today, about 610,000 people in Thailand are now living with AIDS, according to UNAIDS.

"We are still strengthening a very strong platform," said Punnee Pitisuttithum, head of the HIV/AIDS research unit at Bangkok's Mahidol University, which has been involved in vaccine trials since 1994. "Before this trial, we had many disappointments but with this result, we see some light at the end of the tunnel."

Content Courtesy of Daily Nation

I really hope that they can improve this vaccine and turns into a cure.

pomlaksowthai at 10:36AM on Sep 29, 2009

I really hope that they can improve this vaccine and turns into a cure.

I agree, this could save so many lives if they can make this work!!