A large-scale trial has been announced for a vaccine that can significantly reduce people’s chances of being infected with HIV.

The study, which is set to launch in November, is designed to determine whether the vaccine “is safe, tolerable and effective at preventing HIV infection among South African adults”

A smaller Thailand-based study backed by the US had succeeded at creating a vaccine that was 31 percent effective at preventing HIV infection, for 3.5 years after vaccination.

However, the regimen been adjusted to try to increase the magnitude and duration of vaccine-elicited immune responses.

Even a vaccine that does not fully prevent HIV infections would be a huge victory for the research industry – and could have potential to prevent thousands of AIDS-related deaths.

Anthony S Fauci MD of the US-based National Institute of Allergy and Infectious Diseases said: “For the first time in seven years, the scientific community is embarking on a large-scale clinical trial of an HIV vaccine, the product of years of study and experimentation.

“A safe and effective HIV vaccine could help bring about a durable end to the HIV/AIDS pandemic and is particularly needed in southern Africa, where HIV is more pervasive than anywhere else in the world.”

5,400 men and women, aged from 18 to 35 and from groups deemed at-risk of HIV infection, will participate in the study.

The National Institute of Allergy and Infectious Diseases (NIAID) is sponsoring and funding the research, while Sanofi Pasteur and GSK are providing the vaccines for the trial.