AIDS today, gone tomorrow?

When the organisations that most closely monitor global AIDS statistics recently released their annual report, India was at the centre of a major evaluation of the epidemic.

When the organisations that most closely monitor global AIDS statistics recently released their annual report, India was at the centre of a major evaluation of the epidemic. Using new methods of calculating the prevalence of HIV infection, the Joint United Nations Programme on HIV/AIDS and the World Health Organisation lowered their estimates of the number of people living with HIV/AIDS from 39.5 to 33.2 million. More than any other factor, a drop in the estimate of prevalence in India by about a half, to 2.5 million people, accounted for that decline. For years now, India has been at the heart of deliberations about the near-term future of the AIDS epidemic. For some time, experts feared the disease would explode across the subcontinent as it has in Africa. The latest evidence suggests that, thankfully, this has not occurred.

While it is good news that the potential damage wreaked by HIV may be less than once thought, there is a danger that the downward revision of the estimates will produce complacency or, worse, a misguided sense that the epidemic will burn out on its own. True, the new UNAIDS/WHO statistics suggest the number of new HIV infections peaked in the late 1990s, but at an extraordinarily high number. Another 2.5 million people have contracted the virus this year.

Antiretroviral treatments prolong the lives of sufferers, but they are not cures. Those in the West who go on ARV therapy on average live 12 years longer; the minority of sufferers in developing countries who can afford the drugs live an extra six years. In any case, while medicinenbsp;can defer the onslaughtnbsp;of AIDS in an individual, it does not necessarily prevent people from becoming infected with HIV in the first place and thus cannot eliminate the disease from our midst. Only a preventive vaccine can accomplish that.

Lately the field of vaccine studies was rocked by news that what was thought by many to be a promising experimental vaccine, produced by the US company Merck, proved non-effective and might have possibly increased the susceptibility to HIV infection in some trial volunteers. Merck8217;s candidate was tested in the Americas, the Caribbean, Australia and South Africa, but the news has reverberations in India too. For India is not merely a victim of AIDS. Its scientists and policy-makers have become worldwide leaders in the search for a vaccine, a search that must not, and will not, be halted or hindered by the faltering of one product.

Some sceptics believe it is impossible to create an effectivenbsp;AIDS vaccine.nbsp;But research providesnbsp;a solid basis for optimism.nbsp;The human body, we have learnt, is better at fighting off HIV than was previously known. Most people who contract HIV are able, without any outside intervention,nbsp;to suppress the virus for many years; some suppress it indefinitely. A small number are regularly exposed to the virusnbsp;but remain uninfected.

In other words, the bodynbsp;manufactures its own form ofnbsp;partial or complete immunity.nbsp;Finding out how this worksnbsp;is at once a challenge and an opportunity.nbsp;When we understand the process, it may be possible to create anbsp;vaccinenbsp;that mimics and improves uponnbsp;what now appears to be a form of naturalnbsp;resistance.

Apart from Merck8217;s product, there are more than 30 other experimental candidates around the world in various stages of testing. Further analysis of the Merck results may shed light on how best to prioritise the development of those products. India is already playing a role in the invaluable work of testing experimental AIDS vaccines. The National AIDS Control Organisation NACO and the Indian Council of Medical Research ICMR are partners with the International AIDS Vaccine Initiative IAVI in two such trials, one at the National AIDS Research Institute in Pune and another at the Tuberculosis Research Centre in Chennai.

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The failure of Merck8217;s vaccine is likely to spur new thinking about the best way to build an effective vaccine. Indian medicinal chemists are already doing pioneering work in this area,nbsp;via a scientific consortium put together by IAVI and through a partnership between IAVI and the department of biotechnology, which is part of the Union ministry of science and technology.

Research is expensive.nbsp;And vaccine researchnbsp;is notoriously hard to fund.nbsp;People are willing to fight for treatment of diseases they, or their loved ones, have already contracted.nbsp;Vaccines, by definition,nbsp;protect the uninfected, and are often seen by people as a more abstract concern 8212; until the pandemic hits them, by which time it isnbsp;too late.

Sadly, private industry has not invested much in AIDS vaccines. Given the scientific challenges involved, surer profits are to be had developing other products. As such, Merck deserves enormous credit fornbsp;its work in this field.

In the absence of significant private capital, and in view of the very human tendency not to give today8217;s attention to tomorrow8217;s problem,nbsp;the urgent work of finding an AIDS vaccinenbsp;has fallen upon a relatively small band ofnbsp;scientists and activists.nbsp;It is imperative that they receivenbsp;funding, support andnbsp;encouragement from the world health community, international institutions, private philanthropists and foundations such as the Bill and Melinda Gates Foundation and, crucially, governments.

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The expectations from India are among the highest. India, as far as AIDS is concerned,nbsp;is no longer simply a vulnerable nation.nbsp;It is an emerging scientific and technological superpower on whose contribution, intellectual and material, the world is counting.

The writer is president and chief executive officer, International AIDS Vaccine Initiative