It is sobering to look back and recall that three decades ago tens of thousands of children in this country, many of them infants, were being crippled, even killed, by polio each year. The fight to vaccinate and protect our little ones from this dreadful condition has been long and hard; mistakes have been made, and lessons learnt. No Indian child was recorded as having fallen victim to the disease in the past year. Surveillance laboratories are carefully testing stool samples from children as well as sewage, making sure that naturally occurring wild forms of the polio-causing virus are not circulating. Once that has been ascertained, India will be taken off the list of endemic countries. Currently, there are four countries in the list collectively known by the acronym PAIN (Pakistan, Afghanistan, India, and Nigeria). As the other 10 countries in the World Health Organisation's South-East Asian Region have already broken transmission, the process of certifying the whole region as free of indigenous, wild viruses two years' hence can begin. The Americas, Europe, and Western Pacific regions have already been certified as such.
India cannot lower its guard in the matter of immunising its children against polio for a considerable time to come. Even if the wild virus is no longer circulating in India, there is always the risk of an imported strain sneaking in. Wild polio transmission persists in six countries; every one of them except Angola had more cases in 2011 than in 2010. That includes Pakistan and Afghanistan. Last year, another nine countries, including China, were fighting outbreaks caused by imported viruses. At this stage, it is not clear when the wild virus will be vanquished globally. Nor are wild viruses the only problem. The oral vaccines, which have been successfully deployed to battle polio in India and other developing countries, are based on live but weakened forms of the virus. From time to time, those vaccine strains revert to virulence, becoming potentially as dangerous as their wild counterparts. The endgame in polio will therefore need a carefully planned strategy to discontinue the oral vaccine without giving room for the disease to come roaring back. Such a strategy could well involve introducing the inactivated polio vaccine (IPV), which uses killed viruses and is injected. The government must now seriously address these endgame issues. The sort of short-sightedness that led it to shut down a public sector IPV plant being established with French technical assistance in Gurgaon in the early 1990s is impermissible. The goal of freeing ourselves from all polio viruses can be achieved only by resolutely following a clear, well-considered strategy.