Thursday, September 24, 2009

Trial HIV vaccine cuts infection

An experimental HIV vaccine has for the first time cut the risk of infection, researchers say.

The vaccine - a combination of two earlier experimental vaccines - was given to 16,000 people in Thailand, in the largest ever such vaccine trial. Researchers found that it reduced by nearly a third the risk of contracting HIV, the virus that leads to Aids. It has been hailed as a significant, scientific breakthrough, but a global vaccine is still some way off.

The study was carried out by the US army and the Thai government over seven years on volunteers - all HIV-negative men and women aged between 18 and 30 - in some of Thailand's most badly-affected regions. The vaccine was a combination of two older vaccines that on their own had not cut infection rates. Half of the volunteers were given the vaccine, while the other half were given a placebo - and all were given counselling on HIV/Aids prevention.

The results found that the chances of catching HIV were 31.2% less for those who had taken the vaccine. "This result is tantalisingly 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."

The findings were hailed by the World Health Organization (WHO) and the Joint United Nations Programme on HIV/Aids (UN/Aids). They said while the results were "characterised as modestly protective... [they] have instilled new hope in the HIV vaccine research field". Some 33 million people around the world have HIV.

Research into a vaccine has been made difficult because HIV is very good at hitting the immune system, the BBC's health correspondent, Jane Dreaper, reports.


  1. Ok so they gave them the vaccine and gave them counselling and then what happened? Let the subjects loose to have as much sex as they want to see the infection rate? What about those given the placebo? I am very confused as to the technical details of this experiment, so unless someone can give me the details which this article has left rather ambiguous, I have to say that it is raising red flags for me :-(

  2. You know Annette, i never really read much into it until i saw ur comment, then you start asking questions. First of all in such an experiment, isnt it a double-blind experiment where you dont know who got the real vaccine or placebo? so i dont get it, are they saying, its the vaccine thats reducing the rate of HIV?

    I dont blame them as well, when lots of money has gone into an experiment you dont want to come out with nothing positive, so i guess its a matter of lets highlight this, everyone will be so caught up in the numbers that they wont ask questions.