Controversial HIV vaccine strategy gets a second chance

04 November 2016 Vol 354, Issue 6312

In Depth
Controversial HIV vaccine strategy gets a second chance
By Jon Cohen
Science04 Nov 2016 : 535 Restricted Access
Modest success in Thailand inspires South Africa trial
A two-pronged HIV vaccine strategy that delivered lackluster results in a trial in Thailand 7 years ago will get another chance in South Africa. Last week, researchers injected the first of what they hope will be 5400 participants in the $130 million study, which should show once and for all whether the combination actually works. But some researchers say the trial amounts to a waste of money. In the Thai study, the vaccine combination reduced the risk of HIV infection by only 31.2%, and the study failed to show a mechanism that explained this modest benefit, critics say. Backers of the new trial counter that there’s enough evidence to give it another try and argue that even a modestly efficacious vaccine would help South Africa, which has more than 6 million HIV-infected people.