By MediaGlobal
17 June 2008 [MEDIAGLOBAL]: As the number of new HIV infections grows, medical researchers continue to debate the possibility of an AIDS vaccine. And while experts agree that the battle against the deadly disease is far from over, major victories have been made towards securing treatment for those infected.
United Nations Secretary-General Ban Ki-moon highlighted some of these successes last week, when he introduced the report of the Commission on HIV and AIDS and Governance in Africa (CHGA) entitled ‘Securing Our Future’ was presented at the United Nations.
“We have seen an international movement towards universal access to prevention, treatment, care and support – a movement bringing together governments from North and South, civil society and the private sector,” he said.
“We have seen the growth of the Global Fund, which was established within these walls, and which last year alone disbursed more than $10 billion in support of these efforts,” he added.
In 2001, fewer than 200,000 people received antiretroviral therapy (ART). But by the end of 2007, 3 million people had access to antiretroviral (ARV) treatment, of which 2 million were Africans. This is a major victory against the disease. But challenges remain.
“In several countries, prevalence is rising among young people, as well as women and girls. Five million Africans still need treatment,” said Ban.
An HIV-positive woman with her son in Ethiopia.
(Photo: Petterik Wiggers/UNFPA/Panos Pictures)
Last year, there were 2 and a half million new HIV infections and more than 2 million deaths.
In a press conference on the Secretary-General’s report about the global aids response, Peter Piot, Executive Director of the Joint United Nations Programme on HIV/AIDS (UNAIDS), said that for every two people who take ARV drugs, five more are infected.
Yet Uganda is one of the few countries where HIV prevalence has decreased. “The decline in Uganda was due to a multitude of factors. There’s no magic bullet for HIV prevention,” Piot told MediaGlobal.
“But it’s going up again and this is because of [lack of] compliance after prevention programs,” he added.
An AIDS vaccine may be the solution to the epidemic, but the formula behind such a vaccine continues to confound scientists.
Speaking at a press conference at the UN last week, Dr. Anthony Fauci of the National Institute of Allergy and Infectious Diseases expressed doubts about the possibility of a vaccine. “We might never be able to find it,” he said.
Fauci may have good reason for his pessimism. In November 2007, many were hopeful that Merck, a research-driven pharmaceutical company, had found a vaccine against the disease. Merck’s experimental vaccine, V520, was tested in a huge clinical trial that involved 3,000 people in 15 cities. The vaccine contained a common cold virus loaded with 3 HIV genes.
While most vaccines expose the body to weakened or dead viruses in order to stimulate antibodies-proteins that recognize invading cells and mark them for destruction-that approach is not considered safe with HIV. V520 instead stimulated cell-mediated immunity, which ushers in killer T cells- made in the thymus and required for many aspects of immunity-that recognize and destroy viruses and bacteria.
The vaccine failed. Merck’s report on the trial revealed that the drug did not protect against HIV. In fact, it may have increased some people’s susceptibility to the virus.
Dr. David Baltimore, Chairman of the Board of Directors at the American Association for the Advancement of Science (AAAS), said that HIV has evolved to protect itself from the immune system.
“This is a huge challenge because to control HIV immunologically the scientific community has to beat out nature, do something that nature, with its advantage of 4 billion years of evolution, has not been able to do,” he said.
But Seth Berkley, CEO and President of the International AIDS Vaccine Initiative (IAVI), remains upbeat about prospects for the discovery of a future vaccine. Writing in the Wall Street Journal recently, he explained that in the 25 years since HIV was found to be the source of AIDS, progress towards a vaccine has been made.
“We need a vaccine because we cannot stop the epidemic without one,” he said in an interview with MediaGlobal.
On the failed trials, Berkley said, “It was a failure of the trial, but not of science. We were disappointed with the results of the trial, but not completely surprised.”
“Future trials are a certainty,” he added.
But fundamental obstacles lie ahead. Dr. Louis Picker, Associate Director of the Vaccine and Gene Therapy Institute at Oregon Health and Science University, told MediaGlobal, “Creating a vaccine for HIV is not a linear process, as it requires we learn some fundamental answers that we don’t have at the moment.”
Still, Picker remains optimistic about a future vaccine. “Realistically, the soonest we are likely to have a vaccine for widespread use is more than five to seven years away.”
Dr. Larry Corey, principal investigator of the HIV Trials Vaccine Network and head of the University of Washington’s Virology Division and the Fred Hutchinson Cancer Research Center’s Program in Infectious Diseases also believes that a vaccine is a future reality. He told MediaGlobal, “We are 5 to 10 years away.”
Perhaps what is needed is a positive attitude. Berkley wrote in the Journal that if in the past scientists had surrendered to a defeatist, treatment-only doctrine, polio patients would still be in iron lungs. Particularly illuminating is the fact that the production of ARVs was once thought to be impossible.