New HIV Vaccine Cuts Risk Of Infection

Researchers say an experimental HIV vaccine has cut the risk of infection for the first time.

The new vaccine was given to 16,000 people in Thailand, which is the largest vaccine trial ever. 

Researchers discovered that the vaccine reduced the risk of contracting HIV by nearly a third. 

This is considered a scientific breakthrough, even though a global vaccine is still a ways off.

The U.S. army and Thai government carried out the study for seven years on HIV-negative men and women between the ages of 18 and 30 in parts of Thailand.

The vaccine is a combination of two older vaccines that had not cut infection rates.

Half of the volunteers were given placebo, while the other half was given the vaccine.

The participants were tested for HIV infection every six months for three years.

The results showed that the chance of catching HIV were 31.2% less for those that had taken the vaccine.  There was 74 people who did not get the vaccine that were infected and 51 of the vaccinated group got HIV.

The vaccine is based on B and E strains of HIV, which is most common in Thailand, as apposed to the C strain that is dominant in Africa.

"This result is tantalizingly encouraging. The numbers are small and the difference may have been due to chance, but this finding is the first positive news in the Aids vaccine field for a decade," said Dr Richard Horton, editor of the Lancet medical journal.

"We should be cautious, but hopeful. The discovery needs urgent replication and investigation."

Dr Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases said: "For the first time, an investigational HIV vaccine has demonstrated some ability to prevent HIV infection among vaccinated individuals."

"Additional research is needed to better understand how this vaccine regimen reduced the risk of HIV infection, but this is certainly an encouraging advance for the HIV vaccine field."

The World Health Organization and the Joint United Nations Program on HIV/Aids were both excited about the results of the study.

They said while the results were "characterized as modestly protective (they) have instilled new hope in the HIV vaccine research field".

Some 33 million people around the world have HIV.

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On the Net:

• For more information about the Thai Phase III HIV vaccine trial, please see: www.hivresearch.org
• NIH/National Institute of Allergy and Infectious Diseases