Polio Eradication: Is It Time to Give Up?

"A handful of experts have reluctantly concluded that polio may never be wiped out. They are arguing that control may be a better goal than eradication..."

In this article, Deputy News Editor of Science Leslie Roberts outlines the setbacks and shortcomings of the global campaign to eradicate polio, launched by the World Health Organization (WHO) in 1988. Here, Roberts explains why the critics have called for a reassessment; she characterises this debate as "respectful, increasingly public, and with no sign of resolution."

On the one side, David Heymann, who runs the polio eradication programme with Bruce Aylward of WHO, maintains that it is feasible to stop transmission of wild poliovirus in 2006 everywhere except Nigeria and perhaps one corner of India. Supporters of the campaign cite the benefits of an improved, more targeted version of the oral polio vaccine, and stress the enthusiasm and commitment of donors such as Rotary International, the G8, and the Gates Foundation - and of the polio-affected countries themselves. They highlight the fact that it proved relatively easy to stamp out the disease in the United States and other countries, as evidenced in Latin America in the 1980s, when the Pan American Health Organization fine-tuned the mass vaccination strategy known as National Immunization Days (NIDs), during which volunteer vaccinators fan out across the country to deliver polio drops to every child under age 5. The last indigenous case in the Americas occurred in 1991.

However, skeptics point to the explosion of polio out of Nigeria in 2003 with re-infection in many conflict-torn places where it is too dangerous to send health workers - as well as evidence that the virus can circulate undetected even longer than people feared. Social and political problems, some of which pose communication challenges, seem to be overwhelming the campaign's scientific strategy, these skeptics say. For instance, in Nigeria, amid allegations that the polio vaccine was contaminated with the AIDS virus or tainted with hormones to sterilise Muslim girls, several states in the northern part of the country halted polio vaccination. Intense lobbying and research (tests to confirm the vaccine's safety) were strategies used to quell fears. Although Nigeria resumed vaccination about a year later, "the virus still rages out of control." In addition, access and security issues impede efforts such as door-to-door campaigns: "In the Congo, between one-third and one-half [of the country] is just not accessible. You have roaming soldiers, lots of fighting in the eastern third, and it's a huge area," explains one skeptic.

In short, skeptics "worry that the campaign is deluding itself and the world with its 'ever-receding' deadline - originally 2000 and now reset at 2006." They note that the campaign leadership lacks self-awareness, "press[ing] on as if nothing had happened, as if it were 1988"; they characterise this leadership as "captives of their own advertising." For his part, the campaign's David Heymann wishes to keep dialogue flowing: "policies on whether to vaccinate posteradication are still wide open to debate, which he welcomes....'Nothing is cast in stone,' Heymann says." He does feel that polio cannot be controlled through routine immunisation, as some skeptics have urged, because 90% or higher coverage would need to be achieved to keep polio in check. However, he is optimistic, and points to high-level commitment to help the global campaign succeed, such the Afghani president's recent reiteration of his support and the United Nations' Kofi Annan's vow to help with security.

"But optimism is no substitute for a contingency plan, counter the skeptics..."