Polio eradication efforts under threat as vaccine campaigns halted

LONDON — Experts have warned of the “serious threat” that the coronavirus pandemic poses to polio eradication, with immunizations paused even as outbreaks continue in numerous countries.

The fight against polio — which causes paralysis and primarily affects infants — had looked promising, with two of the three wild poliovirus strains eradicated. However, it is now in a precarious position, as vaccination campaigns are halted until at least June because of the risk that health care workers could spread COVID-19 among communities.

Funding is also a concern. The push for polio eradication will require extra resources to make up lost ground, but coronavirus efforts are expected to soak up huge amounts of money and political will.

With the gains against polio already in a fragile position, the new coronavirus “couldn't have come at a worse time,” said David Salisbury, chair of the World Health Organization’s Global Commission for the Certification of Poliomyelitis Eradication.

Prior to the pandemic, wild poliovirus affecting Pakistan and Afghanistan was becoming “out of control,” Salisbury said, citing WHO data, with 104 cases recorded during the “latest onset” in Pakistan on March 16. He said vaccine-derived polio — rare strains of the virus that have mutated from vaccines given to children to protect them against the disease — was also “getting worse” and present in 20 countries in sub-Saharan Africa and Asia, including 53 cases recorded in Angola on Feb. 9.

“All of this is making the achievement of polio eradication all the more difficult because we will have to pick up a worsening situation when services can be restored. ... It was bad enough before [the pandemic]; now it will be worse,” Salisbury said. He described the circumstances as being without “a lot of optimism.”

Huge amounts of money have been poured into the Global Polio Eradication Initiative in recent years, despite stubborn pockets of the disease remaining in some areas. GPEI’s “endgame strategy” for 2019-23 aimed to stop all transmissions of wild poliovirus in the next few years and “eliminate” the risk of future vaccine-derived viruses from emerging.

The strategy is now being reviewed, according to Dr. Hamid Jafari, director of polio eradication for WHO’s Eastern Mediterranean region. How the pandemic plays out, its financial consequences, and the need to adjust the strategy to a “new world” would all be considered in a revision of the current plan, he added.

Jafari said existing polio infrastructure was now being used to respond to the coronavirus crisis, with data management systems, surveillance officers, and community information services all being retrained or adjusted to support the response. Because of the restrictive international travel situation, “a lot of the operational capacity in these countries is coming from the polio programs,” Jafari added.

He said WHO was monitoring opportunities to restart polio vaccination campaigns and is also maintaining polio surveillance, which does not require house-to-house visits.

Jafari said it was key to “preserve polio eradication activities and prepare to get back in a strong way and quickly make up the ground we lose to the poliovirus during this pandemic.” The “tremendous need” anticipated in communities badly affected by the coronavirus and the lockdown would require a response that integrates polio and other essential services. That will be expensive and require coordination with other programs, Jafari said.

Further uncertainty has been caused by U.S. President Donald Trump’s recent decision to withdraw funding for WHO.

Salisbury said that despite the “serious threat,” there was a “glimmer of hope” that widespread lockdowns might blunt the spread of polio. But, he warned, “if social distancing isn’t working and there are no vaccinations, that’s a pretty powerful adverse combination.”

A new type of oral vaccine known as nOPV2, which doesn’t carry a risk of causing new infections, is due to be ready later this year and could be used against ongoing polio outbreaks, although there is a possibility that the vaccine’s delivery will be impeded by the coronavirus pandemic.