Between September and December 2024, four countries in the EU/EEA (Finland, Germany, Poland, Spain) and the United Kingdom reported detections of circulating vaccine-derived poliovirus type 2 (cVDPV2) in sewage samples. This is the first time cVDPV2 has been detected in EU/EEA countries from environmental surveillance.
To date, no human polio cases have been reported and the EU/EEA continues to be polio-free, but such findings call for increased vigilance.
Laboratory analyses likely indicate that the virus has been repeatedly introduced from an unknown area where that specific form of the virus is still in circulation. These recent importations may pose a threat to public health in the EU/EEA and should be monitored closely according to a Rapid Risk Assessment published today by ECDC on this topic.
"Europe has been polio-free for more than 20 years. We have to remain vigilant, maintain high vaccination rates and close any vaccination gaps that exist to prevent any return of this serious disease," said Pamela Rendi-Wagner, ECDC Director.
Poliovirus is highly infectious and can be transmitted easily and silently across wide geographical areas. Therefore, while the EU/EEA continues to remain polio-free, it is vital to maintain adequate vaccine-induced immunity. Polio is a potentially debilitating disease and no specific therapy is available against the virus. Vaccination is the only effective method of protecting against severe disease caused by poliovirus.
Although the majority of EU/EEA countries report vaccination coverage above 90% at the national level, subnational data reveal a much more heterogeneous picture, with only 39% of reporting districts reaching 90% vaccination coverage, which requires constant assessment of vaccination strategies and vaccination coverage from both national and sub-national perspectives. Additionally, according to ECDC estimates, around 600 000 children aged 12–23 months may not have received a full primary polio vaccination course in 2022 and 2023.
The overall risk among vaccinated populations is assessed to be very low, irrespective of the extent of vaccination coverage. The overall risk among under or unvaccinated populations is assessed to be low in areas with high vaccination coverage and moderate in areas with low vaccination coverage.
If polio cases occur, Member States should activate national poliomyelitis response plan; clinicians, particularly paediatricians, should be made aware regarding the possibility of acute flaccid paralysis (AFP) cases caused by poliovirus.
Based on the assessment, ECDC recommends public health authorities reinforce routine childhood vaccination programmes to achieve and maintain at least 90% coverage across all levels of society. It also calls for timely immunisation catch-up campaigns targeting individuals with incomplete or unknown vaccination status, particularly in areas of suboptimal coverage or where environmental sampling has detected the virus.
Additionally, authorities are advised to maintain adequate stocks of inactivated polio vaccine (IPV) and to ensure that all populations with unknown polio vaccination history, receive the vaccine.
Countries are also encouraged to strengthen environmental surveillance to quickly detect any further introductions or circulation of the virus. By improving data collection and surveillance systems, EU/EEA countries can better identify gaps in vaccination, adapt response strategies, and communicate effectively with the public.
Furthermore, public health authorities should develop tailored, context-specific, culturally sensitive interventions to increase vaccination uptake and conduct risk communication activities to highlight the importance of ensuring timely routine vaccination.
ECDC will continue to work closely with national authorities and international partners to monitor the situation, provide guidance, and support efforts to maintain high vaccination levels. Through these collective measures, the EU/EEA aims to prevent poliovirus from returning to communities and safeguard them against an entirely preventable disease.
