Canadian researchers received approval Tuesday from the U.S. Food and Drug Administration to begin testing an experimental and potentially breakthrough HIV vaccine on human subjects with the first phase of clinical trials scheduled for January, the National Post has reported.
The vaccine could be a milestone achievement in HIV prevention because it works similarly to existing vaccines for polio and the flu: by using whole samples of dead viruses to stimulate an immune response in recipients without causing them to contract the disease. The National Post has also reported that the vaccine has gone through preliminary toxicology tests without raising safety concerns.
"None of the researchers in the past have used this approach," lead researcher Dr. Chil-Yong Kang, a virologist at the University of Western Ontario who has been working on the vaccine since 1987, said in an announcement.
Previous HIV vaccines tested on humans didn't use whole HIV-1 viruses as antigens- or substances that trigger the immune system to produce protective antibodies- but rather used small parts of viruses, recombinant DNA, or viruses carrying HIV genes.
In order to test the effectiveness of this new approach, the vaccine will have to undergo three phases of clinical trials which are, as outlined by CBC News:
Phase 1. Beginning in January 2012, this phase will involve 30 HIV-positive people on whom safety will be retested.
Phase 2. This phase will examine immune responses in humans and will involve 600 HIV-negative people who are at high risk of contracting the AIDS virus.
Phase 3. This phase will determine the efficacy of the vaccine and will involve 6,000 HIV-negative volunteers at high risk of contracting the virus.
The clinical trials come in the wake of a disappointing blow earlier this year to HIV prevention efforts. Researchers were surprised to learn that Truvada, a prophylactic drug suggested to prevent HIV infection in gay men, did not work for women during preliminary clinical trials.
Still, researchers continue to develop preventative drugs like Truvada that can be mass produced because treating HIV and AIDS once it's been contracted is possible, but remains difficult and very costly. A major breakthrough in HIV and AIDS treatment came earlier this year in June, when it was announced that a 45-year-old San Francisco man Timothy Ray Brown had been "functionally cured" of HIV.
Doctors were able to completely eliminate the virus from Timothy Ray Brown by giving him a series bone marrow and stem cell transplants. Unfortunately, that line of treatment is not realistic for treating the 35 million people worldwide currently living with HIV-AIDS because it requires a huge amount of time and resources including multiple compatible transplant donors.