Europe’s Polio-Free Status Is Not a Done Deal

The European Regional Commission for the Certification of Poliomyelitis Eradication (RCC) has warned that Europe’s long-held polio-free status could be at risk due to inadequately enforced and outdated action plans for potential outbreaks.

Vaccine manufacturing premises are a specific concern.

“While there is notable progress with implementation of the WHO Global Action Plan for Poliovirus Containment (GAPIV) stringent requirements in the region, the RCC expressed concern regarding containment breaches at several poliovirus-essential facilities, primarily vaccine manufacturing facilities, during the past years,” Shahin Huseynov, MD, technical lead on polio at the World Health Organization (WHO) Regional Office for Europe, told Medscape Medical News. 

Huseynov said the situation in Romania is a particular challenge due to a lack of progress since 2016 in complying with facility regulations and the establishment of the National Authority for Containment. 

Annual reports from European member states indicate no wild poliovirus in circulation in 2023, and that any importations or circulation would have been quickly detected by existing surveillance systems. 

However, according to an RCC report published late last year, six EU/EEA countries, including Austria, Belgium, and Romania, are at intermediate risk for sustained polio outbreaks. 

Now, the RCC is highlighting insufficient immunization coverage, incomplete poliovirus facility containment, and inadequate outbreak preparedness planning as possible threats to Europe’s polio-free status. 

“Poliovirus is a highly infectious disease that spreads rapidly and often silently across far geographic areas to reinfect polio-free areas and countries. […Until] it is eradicated, the message must be that poliovirus is literally only a plane ride away,” Oliver Rosenbauer, spokesperson for polio eradication at the WHO, told Medscape Medical News. 

A spokesperson from the European Centre for Disease Prevention and Control (ECDC) said the agency endorses the WHO’s temporary recommendations for EU/EEA citizens who are residents of or long-term visitors to countries at risk for international spread of polio to take an additional dose of poliovirus vaccine between 4 weeks and 12 months before travel. 

Initial symptoms of poliovirus include fever, fatigue, and headache. Around 1 in 200 infections lead to irreversible paralysis, with 5%-10% of these individuals dying when their breathing muscles stop working. 

Why and How We Immunize Matters

Huseynov noted that while routine polio immunization coverage in Europe is high, with the regional average for three doses at 95%, several countries have below 90% coverage. 

Erwin Duizer, PhD, head of the Netherlands’ National Polio Laboratory, explained to Medscape Medical News that reasons for declining immunization rates vary by country but can include underestimation of the seriousness of vaccine-preventable diseases, decreasing faith in government and public health institutions, and misinformation spread via social media. 

“That polio preparedness seems to be a lesser priority makes sense for an almost eradicated pathogen; [however, polio could] benefit from an improved ‘generic’ preparedness level. Now that COVID-19 preparedness has been scaled down, we in the Netherlands, for example, have time and capacity to update our polio response guidelines,” said Duizer. 

Changing types of vaccination programs could also lead to changing risks.

The oral live attenuated polio vaccine (OPV) is no longer recommended in Europe, as it has the potential to mutate and trigger more virulent strains of polio virus. However, it is still sometimes used alongside the injected inactive polio vaccine (IPV) in areas where the virus is circulating, as they work synergistically to curb further spread.

“The problem is that we have stopped using the OPV and rather use the IPV that does not prevent transmission,” Christine Stabell Benn, professor of global health at the University of Southern Denmark, told Medscape Medical News. 

She added that Denmark recommended three doses of IPV during the first year of life, followed by OPV at 2, 3, and 4 years of age up to the birth cohort born in 1998. 

“I think it makes sense to use a program like the Danish one, using IPV to protect children from polio disease, followed by three doses of OPV to prevent disease transmission and to benefit from the nonspecific immune-strengthening effects of OPV.” 

A Traveling Virus

The WHO said that importations of polioviruses linked to outbreaks in other regions will continue until polio has been eradicated worldwide. 

So far in 2024, several countries in Europe have reported poliovirus detections in environmental samples. In September, Spain reported that it had detected a vaccine-derived poliovirus that emerged in northern Nigeria and had previously been circulating in a number of other countries. 

All detections are being investigated and no cases of paralysis have been reported.

Conflict zones also pose a major threat to vaccine coverage due to disruptions in vaccination campaigns and attacks on health systems and vital infrastructure.

In August, health authorities in Gaza confirmed their first case of polio in 25 years. The same type 2 vaccine–derived polio virus that infected the child was detected in July in six sewage samples taken from different parts of the city. There is concern of a risk for spillover into neighboring countries.

“The most important measure today is to force both parts of the conflict to completely cease fire during the vaccination campaigns,” Professor Antoine Flahault, MD, PhD, director of the Institute of Global Health at the University of Geneva, Switzerland, told Medscape Medical News.

“Allowing appropriate vaccine coverage in the Gaza population will protect both Palestinians and Israelis. And it will protect the rest of the world,” he said. 

To maintain its polio-free status, Huseynov said it will be important for Europe to ensure that it has sensitive surveillance systems, including environmental wastewater surveillance, preparedness mechanisms to respond to events or outbreaks, and strict compliance with containment requirements. 

Annie Lennon is a medical journalist. Her writing appears on Medscape, Medical News Today, and Psych Central, among other outlets.