The results are surprising because until recently, HIV test vaccination failed, prompting many scientists to think that it would never be possible to develop an HIV vaccine.
Speaking in Bangkok, Thailand, the researchers said in the world's largest trial of more than 16,000 volunteers in Thailand, their vaccine reduced the risk of HIV infection by more than 31. %.
The study, conducted under the supervision of the Thai Ministry of Health, tested two vaccines: ALVAC from Sanofi Pasteur (Sanofi-Aventis Group) and AIDSVAX, originally developed by VaxGen Inc. developed and is currently being developed by Global Solutions for Infectious Diseases (a nonprofit established by former VaxGen employees).
ALVAC uses canarypox, a bird virus that has been modified to not cause disease in humans, to introduce three HIV genes into the volunteer body. AIDSVAX contains a protein on the surface of the HIV virus that is genetically modified. These vaccines are not made entirely of viruses so they do not cause infection.
The study was conducted on HIV-negative Thai men and women aged 18-30 who were at risk for HIV infection at an average level. ½ of these were given four doses of ALVAC and two doses of AIDSVAX for six months. The remaining half was injected with a placebo.
All were given condoms, given free counseling and sexually transmitted disease treatment. They will also be tested for HIV every six months and infected people will receive free antiretroviral treatment.
Participants were followed for three years after vaccination. As a result, 51 in the vaccinated group (8,197 persons) were infected with HIV, 31% lower than the other group.
The next target of the study was whether the vaccine would affect the immune system and help keep people with HIV from developing AIDS.
According to estimates by the United Nations Program on HIV / AIDS (UNAIDS), there are 7,500 new HIV infections in the world every year, and in 2007, 2 million people died of HIV / AIDS.