Chasing the vaccine

Vaxgen, a California-based pharmaceutical company, is valiantly seeking to enlarge a faint silver lining as it presents findings of four yea...

Vaxgen, a California-based pharmaceutical company, is valiantly seeking to enlarge a faint silver lining as it presents findings of four years of research on its Aids vaccine. Aidsvax, the first Aids vaccine to be used in widespread trials, reduced the rate of HIV infection by a mere 3.8 per cent among its control group as compared to those who were injected with a placebo. For a vaccine to be considered effective, a 70 per cent decline in infection is routinely deemed necessary. But the pharma company says that among blacks, Latinos and Asians, the vaccine produced dramatically lower incidents of HIV contraction.

So is there cause for cheer? The stock market does not seem to think so, and VaxGen shares plummeted after its research was made public. However, given the pitifully meagre understanding scientists have of the Aids virus more than 20 years after the syndrome started felling its first victims, it certainly is a step forward. The contention that the vaccine could offer protection certain ethnic groups must, of course, be investigated before being accepted right away. An Aids vaccine has been the holy grail of immunologists for two decades now. But they still appear clueless about where exactly to begin. Successful vaccines usually trigger the production of antibodies, so that a pathogen cannot lodge itself in the host. For Aids, researchers are not clear which antibodies are needed to fight the virus. It does not help matters that there are so many HIV strains that tracking them has becoming a sub-discipline in itself. Moreover, most vaccines use a weakened strain of the virus for the disease sought to be prevented. But in the case of HIV, injecting any form of the virus in field trials is considered too dangerous. So, for instance, Aidsvax uses a protein found on the surface of the Aids virus but manufactured through recombinant DNA technology.

In other words progress is bound to be slow. Some leading scientists have, in fact, wondered whether an Aids vaccine is indeed within the realm of possibility. Maybe. But given the fact that more than 40 million carry HIV infection worldwide, with an estimated 3.7 million in India, there really is no option but to soldier on, hoping that finally some laboratory concoction will click.