The US programme to develop an HIV vaccine will shift funding back towards basic research and away from clinical trials of candidate vaccines, officials at the National Institutes of Health announced last week.

The decision follows the discontinuation last year of trials for Merck's candidate HIV vaccine, in which participants showed higher rates of HIV infection than the unvaccinated population. Merck's was one of only three vaccines to make it to large-scale clinical trials. A second had already failed, and there are doubts about the ability of the third to stimulate the immune system.

The vaccine pipeline needs refilling, National Institute of Allergy and Infectious Diseases director Anthony Fauci said on 25 March. “We need to turn the knob in the direction of discovery — that is unambiguous.”