Disappointment as Merck halt HIV trials

Trials for a promising HIV vaccine have been halted after the manufacturer found that they were proving ineffective.

International drug company Merck announced on Friday (September 22nd) that it had been forced stop vaccinating volunteers with the drug, which it has spent ten years developing, after it failed to stop people catching the virus.

Step, the company's international trial involving 3,000 HIV-negative volunteers, found that 24 of the 741 volunteers who had been given the vaccine became infected with HIV, while out of the 762 volunteers who were given a dummy version of the jab, 21 became infected with HIV.

Keith Gottesdiener, head of Merck's clinical infectious disease and vaccine research group said: "It's very disappointing news. A major effort to develop a vaccine for HIV really did not deliver on the promise."

Most of the volunteers for the study, which began in 2004, were at risk of HIV infection, and included sex workers.