GoKawiilPolio vaccination in Pakistan, where the wild-type virus remains in circulation.Credit: Arif Ali/AFP/Getty
If you are below the age of 60, the global quest to eradicate polio has accompanied most of your adult life. During that time, the naturally occurring strain of the virus, also known as wild-type polio, has been eliminated from almost all countries. By 2023, there were just 12 confirmed cases in the whole world: six in Pakistan and six in Afghanistan.
Polio should have been eradicated by now. What’s plan B?
But the polio eradication curve is not flattening to zero. The tiny gap that remains isn’t closing. Polio should be long gone, but remains endemic in Afghanistan and Pakistan, which this year reported a total of 18 confirmed cases, as of 21 July. There has to be renewed urgency to finish the job once and for all. The stakes are sky-high: some disease modellers are forecasting a resurgence of hundreds of thousands of cases a year if the world abandons the cause (K. M. Thompson et al. Expert Rev. Vaccines 21, 1667–1674; 2022).
In countries that recently became polio-free, a kind of complacency is setting in, according to an assessment by the Independent Monitoring Board of the Global Polio Eradication Initiative (GPEI). The GPEI has been striving to eliminate polio since 1988 and does phenomenal work, administering more than one billion doses of polio vaccine to some 400 million children every year. But there are many reasons why the ‘last mile’ is proving difficult. These are articulated in the latest report by its independent monitoring board, published last September (see go.nature.com/4g2evvd), and in a Nature News Feature (Nature 655, 840–842; 2026).
Last mile
The GPEI is facing funding challenges from its international donors. At the same time, vulnerable countries are deprioritizing polio and focusing on more-immediate problems, including maintaining public budgets at a time when the US–Iran conflict is worsening inflation.
Nigeria eliminated wild-type polio in 2016. But in the intervening decade, parts of the country have experienced outbreak after outbreak of what is called vaccine-derived polio, the form of polio virus derived from an oral vaccine, which can mutate into a disease-causing form and spread in communities with low immunization rates. In Afghanistan and Pakistan, where more than US$3 billion has been spent over the past decade on polio eradication, there is no single standout reason why eradication hasn’t been achieved. Disruption during the COVID-19 pandemic could be implicated. There is also continued insecurity in the region, with vaccinators subjected to attacks. Another factor is that some people are refusing vaccines or questioning the need for polio vaccination when other health needs — such as clean water and sanitation — are not being met. These are complex and delicate topics that governments and donors are trying to address.
New world disorder
Behind these developments looms a bigger problem: a shift to unilateralism, which is threatening the multilateral endeavours on which public-health initiatives such as polio eradication are built (E. Petersen et al. Int. J. Infect. Dis. 165, 108472; 2026). When, in January, the United States withdrew from the World Health Organization, that also ended its funding for the WHO’s multilateral polio eradication efforts. For the GPEI, the US withdrawal has meant a 30% budget cut this year, which is likely to continue into 2027.
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