Thursday, September 24, 2009
New AIDS Vaccine Shows Modest Success
A new AIDS vaccine, called RV 144, was tested on 16,402 volunteers in Thailand and worked to protect 31% of the test group against infection. One-half of the 16,402 volunteers were given six doses of two vaccines in 2006 and the other half were given a placebo (basically a dummy shot). All participants received regular HIV tests over the next three years. Of those who received the placebo, 74 became infected, and of those who received the vaccine, only 51 did. In the over 20-years history of AIDS vaccine trials, this is the first time a vaccine has yielded even part-success.
The clinical trial, however, doesn’t necessarily equal a breakthrough, according to one of the trial’s backers. The researchers are not sure why the vaccine worked. The vaccine consists of a combination of two genetically engineered vaccines, neither of which ever worked on humans before. The vaccine tested in Thailand was designed to fight against a common strain of the virus found in Southeast Asia. The strain found in Southeast Asia is different than that found in Africa, the U.S. and elsewhere, and there is no certainty the vaccine would yield similar results in these different strains, even if modified.
Although the protection results of the vaccine were modest, its significance rests in the creation of the vaccine itself.