Researchers have announced that results from the world’s largest HIV vaccine trial have shown that a vaccine can prevent HIV infection in a general adult population.

The results of the trial, which involved 16 395 HIV-negative adult male and female volunteers in Thailand, revealed that the chances of catching HIV were 31.2% less for those who had taken the vaccine.

The trial was carried out by the Thai government with help from the US Army and has been hailed as extremely positive by the World Health Organization and the Joint United Nations Programme on HIV/AIDS (UNAIDS).

The Phase III trial took place as a test-of-concept for the novel RV144 HIV vaccine regimen, which is a combination of two different candidate vaccines developed by Sanofi-Pasteur and the non-profit organisation Global Solutions for Infectious Diseases.

The vaccine was administered to half the volunteers in the programme, while the other half were given a placebo. All candidates were also provided with counselling on HIV/AIDS prevention.

UNAIDS has, however, warned that more work has to be done to analyse among other things the duration of protection before licensure is possible.

According to the AIDS body, licensure at this point in time may not be possible solely on the basis of this study’s results. It also remains to be seen if the two specific vaccine components are applicable across diverse host genetic backgrounds and different HIV subtypes.