The eradication of polio is within reach, but it is too early for self-congratulation.
Just 25 years ago, some 350,000 people contracted polio every year. So far this year, just 60 cases have been reported across four countries worldwide. No wonder, then, that some can foresee world leaders slapping one another on the back for ending polio's scourge on humanity in a few years' time, much as their predecessors did in 1980 when the world was declared smallpox-free.
The Global Polio Eradication Initiative started in 1988 to target poliomyelitis, a paralysing viral disease that mostly affects children. Some US$9 billion later, the result is the lowest number of cases ever tallied, as well as the fewest countries affected.
But it is too early for self-congratulation and complacency. The polio-eradication campaign faces a US$1-billion budget shortfall over the next two years that threatens to erase this year's hard-won successes. Despite a long history of mismanagement and missed deadlines (goals of ending viral spread by 2000 and 2005 passed the programme by, and the same is likely to be true of 2012), the world has come too close to vanquishing this ancient disease to fail to see the task through.
If aggressive vaccination campaigns stop, the virus is likely to rebound more viciously than ever.
If aggressive vaccination campaigns stop, the virus is likely to rebound more viciously than ever in Nigeria, Afghanistan and Pakistan — the three countries never to end its spread — and in the countries they border. China, which was declared polio-free in 2000, is now battling an outbreak in its northwestern Xinjiang province, imported from neighbouring Pakistan. Bruce Aylward, an assistant director-general at the World Health Organization who is leading the eradication campaign, warns against the “false premise” that polio can be safely contained as a rare threat in a few endemic countries.
The world's wealthier countries must meet their financial commitments to polio eradication, even in these lean economic times, and countries that have not yet chipped in ought to. Nigeria, Pakistan and Afghanistan have much more pressing public-health concerns than polio, such as high infant mortality. They are battling the virus for the world's sake and not their own.
Western countries, fast-developing nations and oil-rich Middle Eastern nations such as Saudi Arabia could all do more to help end polio. Rotary International, the Bill & Melinda Gates Foundation and other philanthropic donors need to keep up their already substantial support.
If donors need a reason to think their money will be well spent, they should look no further than India, which has not reported a case of poliomyelitis since January 2011. The country of 1.2 billion was considered one of the hardest in which to eliminate the disease.
India's success may not offer specific lessons to Nigeria, Pakistan or Afghanistan. Each country — and, indeed, each region where polio still circulates — has its own set of challenges that range from religion-inspired vaccine refusal to domestic terrorism to local government corruption.
An emergency action plan announced by the polio-eradication initiative in Geneva last week is a good start (see page 563). It is right to emphasize local solutions and accountability at all levels. But health officials need to remain flexible if the current plan fails, particularly in Nigeria, which is facing its high-transmission season and is battling outbreaks of three different viral serotypes.
Officials involved in the eradication effort are considering introducing injected vaccines, in conjunction with the oral vaccines in use in endemic countries. Injected vaccines could boost immunity in children who do not receive the multiple doses of oral vaccine needed to ensure protection. Such a move could also accelerate the transition from a live oral vaccine, which carries the rare side effect of triggering the disease it is supposed to fight, to inactivated injected vaccines.
It is tempting to think even further ahead, beyond polio eradication. The World Health Assembly, for example, is already considering a measles-eradication initiative. It should proceed cautiously. The polio initiative, which emphasized vaccination campaigns, may have come at the expense of routine child immunization programmes in some countries.
Measles could offer a distraction from this vital work. Some countries would be unwise to focus on this goal before achieving a high level of routine immunization against diseases such as diphtheria and tetanus.
While the polio-eradication effort was setting out its proposals last week, the World Health Assembly quietly endorsed a separate plan, which sets routine vaccination coverage targets of 90%, and aims for steep reductions in child mortality from vaccine-preventable diseases by 2020. If these goals can be achieved, there may be less political backslapping than for vanquishing polio, but the people of the world should be just as grateful.
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A war not yet won. Nature 485, 547–548 (2012). https://doi.org/10.1038/485547b