With the observance came a landmark report from the World Health Organization (WHO): wild poliovirus type-3 (WPV3) has been eradicated, its last case having been observed in Nigeria in 2012, in what the agency described as a “historic step” following in the footsteps of the global eradication of wild poliovirus type-2 (WPV2) and smallpox. Yet, as experts remind us, there is still further work to be done before the world can officially be declared free from polio – and complacency cannot be tolerated.
“We face a very hard twelve months,” says Michel Zaffran, director of polio eradication at the WHO, as cases in Afghanistan and Pakistan – the world’s two remaining polio hotspots – remain. Cases of the wild poliovirus type-1 (WPV1) have more than doubled in 2019, from 33 in 2018 to 88 so far this year. Pakistan alone has witnessed 62 cases in 2019, compared to eighteen in 2018. The continued presence of polio in the world and upsurges in cases led to polio being designated a Public Health Emergency of International Concern by the WHO in 2014, only the second such announcement in the agency’s history.
As The British Medical Journal points out, “vaccine refusals and deadly attacks on polio workers have hampered immunisation efforts. Overall, the disease has made a small comeback since 2017, with case numbers now rising for the first time in decades.” Whilst the news of WPV3’s eradication serves as “a morale boost for the global campaign to eradicate polio”, it also serves as a call to action to sustain momentum and avoid complacency.
“Abandoning the effort now will not keep things at the current level,” Walter Orenstein, associate director of the Emory Vaccine Center, told Devex. “We will get a major resurgence. And that’s what we need to explain to people: Don’t think if you stop, it will be over. It will not be over and it will get a lot worse.”
For India, which was certified as polio-free by the WHO in 2014, the lessons of World Polio Day are manifold. As recently as 2008, India accounted for as many as half of the global polio cases. Against these odds, its last case was reported in 2011 and it was removed from the list of polio-endemic countries the following year.
Health Issues India has written in the past about the importance of vigilance against diseases such as polio which are declared eradicated. Momentum behind vaccination campaigns cannot be allowed to subside: they must be continued, particularly given the prospect of WPV being imported from Afghanistan or Pakistan. In particular, India must climb the final hurdle of transitioning from the oral polio vaccine (OPV) to the inactivated polio vaccine (IPV). There is a risk, albeit small, that the OPV can cause vaccine-associated paralytic poliomyelitis. This has been described as India’s endgame in its fight against polio.
“The achievement of polio eradication will be a milestone for global health. Commitment from partners and countries, coupled with innovation, means of the three wild polio serotypes, only type one remains,” commented WHO Director-General Dr Tedros Adhanom Ghebreyesus. “We remain fully committed to ensuring that all necessary resources are made available to eradicate all poliovirus strains. We urge all our other stakeholders and partners to also stay the course until final success is achieved.”