| In the News |
| Opinion veering against AIDS vaccine research |
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Scientists and researchers are beginning to debate whether, after 25 years of research into an AIDS vaccine, it’s time to admit that the money can be better spent elsewhere |
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Two recently published articles have questioned both the usefulness of research to produce an AIDS vaccine and the amount of money invested in it. A poll of more than 35 British and US AIDS scientists and researchers, by the British newspaper The Independent, revealed that scientific consensus on the prospect for development of an effective preventive AIDS vaccine is bleak at best. In a column in the Los Angeles Times titled ‘No Results? No Research Money’, Dr Homayoon Khanlou, chief of medicine, AIDS Healthcare Foundation (AHF), and Michael Weinstein, AHF’s president, also question whether it is worthwhile to pour billions of dollars into vaccine research that seems to be going nowhere. In the Independent article ‘Is it time to give up the search for an AIDS vaccine?’, by Steve Connor and Chris Green, nearly two-thirds of respondents said that an HIV vaccine will not be developed within the next 10 years, and a substantial minority admitted that an HIV vaccine may never be developed. A majority, though, said that a vaccine would be the most effective way of preventing the spread of the virus given the failure of many education programmes. The article points out that an important finding to emerge from the failed clinical trial of the most promising prototype vaccine, manufactured by the drug company Merck, was that the animal model used for more than a decade -- testing HIV vaccines on monkeys before they are used on humans -- does not work. So, prototype HIV vaccines which appear to work well when tested on monkeys infected with an artificial virus do not work when tested on human volunteers at risk of HIV. Anthony Fauci, director of the US National Institute of Allergy and Infectious Diseases (NIAID), near Washington, told The Independent that the animal model -- which uses genetically engineered simian and human immunodeficiency viruses in a combination, known as SHIV -- failed to predict what will happen when a prototype vaccine is moved from laboratory monkeys to people. “We’ve learnt a few important things [from the clinical trial]. We’ve learnt that one of the animal models, the SHIV model, really doesn’t predict very well at all,” he said. “At least we now know that you can get a situation where it looks like you are protecting against SHIV and you’re not protecting at all in the human model -- that’s important,” he said. The outcome of a high-level meeting convened by Dr Fauci in March, in Bethesda, Maryland, was a decision to refocus the vaccine effort away from expensive clinical trials towards more fundamental research to understand the basic biology of the virus and its effects on the human immune system. In their article in the Los Angeles Times, Homayoon Khanlou and Michael Weinstein take issue with an article that appeared in the Wall Street Journal ‘Keep funding the AIDS vaccine’ by David Baltimore and Seth Berkley, CEO and president of the International AIDS Vaccine Initiative, in which the authors argue that though vaccine development is hard, it must be pursued. Khanlou and Weinstein believe that this is not “a credible response to recent criticism levelled at the ballooning US budget for AIDS vaccine research and the meagre results it has produced. The argument is particularly weak when you consider that nearly 1 billion in public funding is poured annually into this fruitless quest, while millions globally lack access to the revolutionary, life-saving AIDS treatment that was developed more than 12 years ago: antiretroviral medication”. The authors allege that the Merck vaccine trial was not only a failure but it actually “endangered lives by increasing the likelihood that study participants would contract the virus”. After 25 years of repeated AIDS vaccine failures at high cost to taxpayers, to call for more human clinical research “defies common sense and endangers lives”. They say that researchers still do not have significant insights into the basic mechanisms of the virus and the human body’s response to it. They recommend that money being poured into vaccine research could more profitably be diverted to increasing access to treatment that can cost as little as 50 cents a day. A better way to deal with AIDS is to “break the chain of infection” by stopping an infected person from passing it on to others, an initiative that has had some success. “Effective pre- and/or post-exposure prophylaxis treatments are an example of a possible approach” for the 33 million people currently estimated to be carrying the virus. “A focused antiretroviral pre-prophylaxis effort in high-risk populations, such as commercial sex workers, would be a highly cost-effective way to prevent the spread of infection.” The authors say that there is increasing evidence that patients with undetectable viral loads -- achieved through antiretroviral treatment -- have a much lower rate of transmission, “perhaps a rate even lower than could be achieved with a successful vaccine”. Money should be put into increasing access to these lifesaving drugs. “What might a nearly $ 1 billion annual investment in the worldwide scale-up of antiretroviral treatment buy in terms of transmissions prevented,” they ask. Over the years, the scientific community has come to a consensus: an investment in basic science is needed. The article says that researchers with Berkley’s International AIDS Vaccine Initiative and the Centre for HIV/AIDS Vaccine Immunology that use US public funds for HIV vaccine research plan to focus on basic science research such as the genetic sequencing of new HIV viruses, an investigation into how genetic factors might control HIV infection and inquiry into the possible reasons why some people exposed to HIV do not progress to AIDS. Some HIV affected people interviewed for the Independent article, however, still pin their hopes on vaccine research. Winnie Seruma, 46, said that abandoning research for a vaccine would mean a loss of hope for millions of people. When she was diagnosed 20 years ago, the first drugs had just come on the market. “A lot of people had said before then that there was no hope and that all efforts should be put into prevention. But look where we are now. We cannot lose hope; we need to invest in a vaccine,” she said. ‘Philippe B’, 42, who has lived with HIV for 11 years, is afraid of the fact that he is becoming resistant to new drug treatments and said a preventive vaccine could be the only hope for the future. Source: The Los Angeles Times, April 25, 2008 |