AIDS Vaccine Breakthrough in Thailand

Over 16,000 people – men and women -- from communities in the southern Thai province of Rayong participated in the six-year-long clinical trial.

Dr Supachai Rerks-Ngarm from Thailand’s Ministry of Public Health said that the “results showed that the vaccine has an efficacy of 31.2 percent. This means that the vaccine can reduce the risk of infection in the vaccinated group compared to the placebo group. This is the scientific breakthrough.”

“This is the first time that we can prove that the vaccine can prevent the infection from developing in the vaccinated group -- this is the first stepping stone to developing vaccines for supplementing preventative measures.”

Biggest trial of its kind

The trial was the first such large-scale community-based HIV vaccine efficacy trial in the world. It cost some 123 million US dollars over six years. It was carried out by the US Army, the Thai Ministry of Public Health, education institutes in Thailand and non-government organisations.

The volunteers -- none of which had HIV -- were all aged between 18 and 30. This is a key high risk group when it comes to contracting HIV.

Half of the group received placebos and half were vaccinated. According to the results, 74 of those who had received placebos became infected with HIV compared with 51 who were vaccinated with a two-vaccine combination.

Positive news for the vaccine community

Alain Bouckenooghe, the Asia Pacific head of clinical research and development at sanofi pasteur, which manufactures one of the vaccines said that it was positive news and this was very much needed.

“Over the past few years, there have been several setbacks. This is the first phase-three trial that shows that an efficacious and safe vaccine can be designed. It will require more work but this is definitely good encouragement.”

Bouckenooghe added that the fact that two different vaccines had been used sequentially and in several doses enabled a broader and deeper immune response.

One step closer but threat remains

The US ambassador to Thailand, Eric G. John, cautioned that the threat of AIDS still remained high despite the developments: “Many nations around the globe are still struggling with serious HIV/AIDS epidemics. Even in places like the US and Thailand there is the threat that AIDS could reach crisis proportions. An HIV vaccine remains our best hope to fight this dreadful disease. That is why I am here today to help announce that we are now one step closer to finding a HIV vaccine.”

More than five million people in Asia live with HIV. The United Nations estimates that globally 7,500 people are infected with the virus each day. According to UNAIDS, the virus claimed the lives of two million people in 2007.

Some progress has been made in slowing the rate of infection in countries such as Thailand, Cambodia and Myanmar but in Indonesia, Pakistan and Vietnam infection rates continue to climb.

Medical officials said the results of the trials and the data would be closely examined and the volunteers would be briefed over the coming weeks as to who had received the vaccine and who had not.

Author: Ron Corben
Editor: Anne Thomas