Global efforts to eradicate wild polio have faced repeated setbacks as eradication targets continue to be missed, according to a report published by Nature. Although Nigeria experienced its last two cases of the wild virus in August 2016, leaving the virus circulating only in Afghanistan and Pakistan, subsequent targets set for 2019, 2023, and 2025 have passed without stopping transmission.
Global Polio Eradication Initiative Funding and Vaccine Administration
Over the past decade, more than US$3 billion has been spent fighting the virus in Afghanistan and Pakistan, alongside the administration of billions of doses of oral polio vaccine (OPV). Modellers calculate that the campaign has prevented between 2.5 million and 6 million cases of paralysis. Of the three types of wild polio that previously circulated, only type 1 remains.
Wild Polio Case Fluctuations and Environmental Detections
Despite these measures, wild polio cases have fluctuated significantly, dipping to 22 cases in 2017 before rising to 176 in 2019, falling to 6 in 2021, and rebounding to 99 in 2024. Similar patterns have been observed in the detection of the virus in the environment.
Arshad Quddus and David Salisbury Perspectives on Eradication
Campaign leaders maintain an optimistic outlook. Arshad Quddus, acting director of the Global Polio Eradication Initiative (GPEI), stated that progress is still being made toward zero, noting that polio is transmitted less often and in smaller areas, with some former core reservoirs seeing no cases in more than a year. David Salisbury, chair of the GPEI’s Global Commission for Certification of Poliomyelitis Eradication, noted that type 1 is no harder to quash than other types, citing its successful eradication elsewhere.
However, researchers remain divided on the outlook. Kimberly Thompson, who studies health economics at Kid Risk, a non-profit consultancy in Orlando, Florida, concluded that We’re not heading towards success
and stated that In theory, eradication is possible, but in practice, it is not,
according to Nature. While some researchers have suggested the oral vaccine is failing to trigger sufficient immunity in Afghanistan and Pakistan compared to elsewhere, most experts maintain that the difficulties are operational rather than scientific.
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