Emilio Godoy
MEXICO CITY, Aug 7 2008 (IPS) – We need to get away from this home-run mentality to research. Science is incremental, said Alan Bernstein, executive director of the Global HIV Vaccine Enterprise, referring to unrealistic public expectations with regard to the search for an AIDS vaccine and for vaginal microbicides that could help prevent infection.
In the mid-1990s, the scientific community and pharmaceutical industry exuded optimism with respect to the chances of developing a vaccine to curb the world s most deadly epidemic. A decade or so later, the mood is less upbeat, although the enthusiasm has not been entirely dampened.
A vaccine candidate developed by the U.S. based pharmaceutical company Merck Co. was derailed last year after it had made it to late-stage human trials.
This is only the second failed attempt to develop a vaccine, Dr. Seth Berkley, president and founder of the International AIDS Vaccine Initiative (IAVI) told IPS at the 17th International AIDS Conference in Mexico City, which ends Friday. We are still hopeful, because there are several projects underway, and because millions of lives could be saved.
Founded in 1996, IAVI is a not-for-profit scientific organisation whose mission is to ensure the development of a safe, effective and accessible HIV vaccine. It is operational in 23 countries and has a network of clinical trials in India, Kenya, Uganda, Rwanda, South Africa and Zambia and an annual budget of 84 million dollars.
Our objective should be to stop this virus, and the best way to do so is with a vaccine, said Bernstein.
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There are currently 27 AIDS vaccine projects underway, half of which have made it to human trials. In 2006, 13 new clinical trials began in eight countries, including Brazil. Since 1987, when the first human trial of an HIV candidate vaccine was conducted, more than 30 candidates have been developed.
Only a low-cost, safe and highly effective vaccine that works in all circumstances can put an end to the epidemic, said Simon Noble, editor of the IAVI Report.
The bottom line is that we need a long-term solution to this epidemic. We need a vaccine if we are to turn the tide on AIDS, said Berkley.
According to the Joint United Nations Programme on HIV/AIDS (UNAIDS) global report 2008, there were 33 million people living with HIV worldwide in 2007, and less than three million were receiving life-extending antiretroviral treatment.
IAVI estimates that at the very least, a vaccine would prevent 28 million new infections between 2015 and 2030.
Scientists are undertaking a shift in focus in HIV vaccine research, away from the traditional approach to vaccines of inducing antibodies.
But, as Dr. Tadataka Tachi Yamada, executive director of the Bill Melinda Gates Foundation s global health programme, pointed out, nine out of 10 human trials fail.
In any case, a vaccine would not be ready for at least two decades. Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID) in the United States, estimated that a vaccine could be available in 2031, when there would be 80 million people living with HIV.
That is a symbolic date. UNAIDS launched the AIDS 2031 research and advocacy project to gather a broad range of expert opinions on finding a solution to the epidemic from now until that year, which will look at technologies, advocacy, financing and prevention, and provide its first report in 2009.
At this week s conference, developing countries urged that clinical trials not be brought to an end. Omu Anzala, associate professor at the University of Nairobi School of Medicine, said it would be a mistake to shut down clinical trial centres in Africa because of the failure of vaccine candidates.
It has taken Africa four to five years to build the infrastructure and capacity for us to be able to carry out vaccine trials, said Anzala, who is also director of the Kenya AIDS Vaccine Initiative (KAVI). We cannot stop now. We are ready and are going to be a part of the solution.
Nor has research on vaginal microbicides brought definitive results. Trials are being conducted in Belgium, Britain, Cameroon, the Dominican Republic, Kenya, Malawi, Puerto Rico, South Africa, Tanzania, Thailand, Uganda, the United States, Zambia and Zimbabwe.
Microbicides are products that can be applied inside the vagina to protect against HIV or other sexually transmitted infections. They can take the form of gels, creams, vaginal rings or suppositories, and should ideally be safe, low-cost, effective and easy to use.
Research is being carried out on a number of different microbicides. One of the main candidates is dapivirine, which should reach clinical trials in 2010.
Microbicides, which could incorporate antiretroviral drugs, are among the most promising anti-HIV products being developed, said Zeda Rosenberg, CEO of the International Partnership for Microbicides. They would give women a powerful new way to protect their own health, she added.
The trials should take place in countries with the greatest need of anti-HIV options, said Rosenberg. She also said they should be tested in the places where the microbicides would be used, taking into account effectiveness, risks, acceptability and adverse effects among key populations.
This week s conference, which has drawn nearly 25,000 representatives of governments, international bodies and non-governmental organisations from around the world, has provided few new developments in the field of medicine.
One novelty revolves around a report published by The Lancet on research on an anti-HIV pill that could be taken prior to engaging in sexual relations. The researchers are focusing on antiretroviral drugs already used to successfully prevent transmission from HIV-positive mothers to babies during birth.
The trials involve HIV-negative intravenous drug users, heterosexual men and women and homosexual men in the Americas, Africa and Asia, says the report in the specialised journal, which states that the trials are showing great promise.
I would say we re between first and second base, said Bernstein, referring to progress towards a vaccine.
The next International AIDS Conference will be held in Vienna, Austria in 2010.