In the lab, a vaccine for the dying

Unless the world has a vaccine against HIV/AIDS, the numbers will only continue to increase. Experts agree that a safe, effective and affordable vaccine is the only way to stop the pandemic. According to a WHO 2001 report on macroeconomics and health, ‘‘the development of effective vaccines is the highest research priority in the field of HIV/AIDS.’’ However, the world is several years away yet from a vaccine that can guarantee even 50 per cent efficacy. Of about 30 candidate vaccines in the world, only one — AIDSVAX, developed by a California-based biotech firm — is in Phase III trials.

Even if someone did develop a vaccine, getting the science right is only part of the search. This is so for several reasons. Historically, vaccines have never been introduced into the developed and developing worlds simultaneously. Vaccine developers — typically based in first world laboratories — have held international patents or licenses on their products, and they have been made affordable and available to the developing world after a minimum gap of 15 years. And given that 95 per cent of the existing 40 million people with HIV/AIDS lives in developing countries, one can imagine the disease burden on governments in 15 years.

Also, the HIV/AIDS virus itself presents many challenges to scientists. Nine genetic variations (or subtypes) of the virus, from A through J, are in circulation in different geographical areas. In India, subtype C is prevalent, while in Europe and America, subtypes A and B are common. Subtypes have further manifestations in strains — scientists estimate that in India alone, more than 140 strains of the HIV virus exist.

Thus, even if a vaccine is developed in the USA, it may not be effective in India. The need, then, is to develop vaccines indigenously — each country has to mobilise its own resources to develop vaccines to manage its HIV/AIDS burden. Of course, this has to be concomitant with continuing education and access to ART.

But do developing countries, which witness the highest prevalence rates of HIV/AIDS, have the technological prowess to develop their vaccines? For instance, scientists at the National AIDS Research Institute (NARI) in Pune have isolated six gene strains and performed their DNA sequencing, but India lacks the knowhow to transform the knowledge into a candidate vaccine which can then be used in clinical trials.

Acknowledging the work done by the NARI, a subsidiary body of the Indian Council of Medical Research, the National AIDS Control Organisation signed a MoU last month with a New York-based NGO, the International AIDS Vaccine Initiative, to further the country’s research. Under the agreement, IAVI (which supports similar vaccine development partnerships in several countries) will act as a conduit between the Indian government and a Boston-based biotech firm, Therion Biologics, to develop a Modified Vaccinia Ankara (MVA) vaccine. ‘‘We hope to have it ready for Phase I clinical trials by December 2003,’’ says Dr Lalit Kant of the ICMR. If the trials are successful, Therion is committed to licensing its patented vaccine development technology to an Indian firm, so that the vaccine can be indigenously manufactured and tested for Phases II and III.

Why would an American biotech firm be interested in transferring its technology for a vaccine which may not even be of use in the developed world, given that it’s for a different subtype? As it is, the annual global market for vaccines is only US $4 billion, compared to the $400 billion global drug market, according to Pfizer’s Annual Report 2000. Compared to the market for therapeutics, vaccines spell low profit margins for drug MNCs, because low-income countries, which most need them, cannot afford to pay high prices.

But Dr Vijay Mehra, a scientist at IAVI, says globalisation has wrought a change in the way companies see things. ‘‘Companies the world over are beginning to realise that HIV/AIDS is a global problem. Therion agreed to it because it looks good on their social profile. Also, they get to keep the marketing rights for the developed world, while we keep the rights for the developing world, if a successful vaccine works out,’’ she explains. That, of course, remains a big ‘‘if’’.