A major trial in Thailand to find a possible vaccine against the HIV-AIDS virus has ended in disappointment for researchers. Preliminary results from the huge AIDSVAX trial in Thailand shows that the experimental vaccine does not work, said a representative from the vaccine makers, VaxGen.
The volunteer Thais given the vaccine were no less likely to contract HIV, and the vaccination did also not slow the progress of the terrible HIV-AIDS disease.
VaxGen's president Donald Francis said the failure from the trial in Thailand called on the world's research community to redouble their efforts to find a successful vaccine to stop HIV-AIDS.
While earlier trials in other countries had not offered compelling evidence that the AidsVax vaccine was likely to succeed, in Thailand it had reached it's final stage of testing, in which large numbers of Thai people were given an injection with the vaccine to see how well it performed in wider society. However, the announcement from VaxGen this week confirms earlier signals from other test areas that success was unlikely.
While there are no major side-effects for vaccinated people, there was no difference between vaccinated and unvaccinated Thais when it came to vulnerability to HIV. In all, more than 2,500 drug users in Bangkok, Thailand were involved in the latest test, with half given of them given the actual vaccine and the other half a harmless placebo injection with no ingredients.
During the time of the trial-period, 105 of the volunteers that had received the placebo caught HIV-AIDS and 106 of the volunteers that had been injected with the AidsVac vaccine also caught HIV-AIDS.
The rigorous make-up of the trial in Thailand mean that the results are very reliable, and the attention of researchers is now likely to turn towards other Aids vaccine projects currently underway in Africa and elsewhere in the world.
A number of potential of the newer test-vaccines are currently at an advanced stage of testing, although final results will not be available for some time. Hopes dashed
Donald Francis said: The negative outcome of the Thailand trial is one more reminder of how difficult it is to combat HIV-AIDS and how important it is for the whole International public health community to redouble the effort to try to develop an effective vaccine against HIV-AIDS.
Although we are very disappointed with the outcome of the test in Thailand, VaxGen and our Thai collaborators have created a test model that can be used around the world for advanced clinical research of other trial HIV vaccines.
Results released in February this year revealed that a trial test on 5,000 person showed no advantage in white people, but some prospect of success could be likely for African and Asian populations. The results from the huge trial in Thailand are a blow to the researchers who were encouraged by February's test results.
The AIDSVAX vaccine used in the trial in Thailand does not actually contain any genetic material from the deadly virus itself, but just synthetic constructed versions of the proteins found in the virus. The idea was that the human immune system would become sensitive to these proteins, and generate anti-bodies that would attack any virus resembling the HIV-AIDS virus.
