According to a release from the European Centre for Disease Prevention and Control (ECDC), globally, as of August 9, 19 cases of polio due to wild poliovirus type 1 (WPV1) and 223 cases due to circulating vaccine derived poliovirus (cVDPV) have been reported this year.
In 2022, the cVDPV cases have been reported in 15 countries, with 93% of the cases attributed to cVDPV type 2 (cVDPV2).
Following the detection of sewage samples positive for poliovirus type 2 (PV2) in London, United Kingdom, the UK health authorities advised a targeted booster dose with inactivated polio vaccine (IPV) to all children between 1 and 9 years of age in all London boroughs to ensure a high level of protection against the virus and to limit its further spread. Some of the vaccine derived poliovirus type 2 (VDPV2) isolates found in the UK were genetically linked to VDPV2 isolated from a polio case that had been reported in July 2022 from New York, USA, as well as to environmental samples collected in New York, USA, and Greater Jerusalem, Israel.
ECDC assesses the situation in the EU/EEA as follows:
The EU/EEA, as well as the UK and the wider WHO European Region have remained polio-free since 2002. Inactivated polio vaccines are used in all EU/EEA countries.
As long as there are non-vaccinated or under-vaccinated population groups in European countries and poliomyelitis is not eradicated globally, the risk of the virus being reintroduced in Europe remains. Two EU/EEA countries (Poland and Romania) and one neighboring country (Ukraine) remain at high risk of a sustained polio outbreak following wild poliovirus importation or the emergence of cVDPV, due to sub-optimal program performance and low population immunity, according to the European Regional Certification Commission for Poliomyelitis Eradication (RCC) report from September 2021 assessment, referring to data of 2020. According to the same report, 11 EU/EEA countries are at an intermediate risk of sustained polio outbreaks.
The continuing circulation of wild poliovirus type 1 (WPV1) in Pakistan and Afghanistan and detection of four WPV1 cases in Mozambique in 2022 genetically linked to a strain from Pakistan show that there is still a risk of the disease being imported into the EU/EEA. Furthermore, the worrying occurrence of outbreaks of circulating vaccine-derived poliovirus (cVDPV), which emerges and circulates due to lack of polio immunity in the population, shows the potential risk for further international spread.
To limit the risk of reintroduction and sustained transmission of WPV and cVDPV in the EU/EEA, it is crucial to maintain high vaccine coverage in the general population and increase vaccination uptake in pockets of under-immunized populations. The EU/EEA countries should review their polio vaccination coverage data and ensure there are no immunity gaps in the population and there is capacity to identify virus circulation through well-performing surveillance systems.
ECDC endorses WHO’s temporary recommendations with regard to EU/EEA citizens who are residents or long-term visitors (>4 weeks) in countries with the potential risk of international spread of polio, that is, they are recommended to receive an additional dose of poliovirus vaccine between four weeks and 12 months prior to international travel.
ECDC is closely monitoring the polio situation in the EU/EEA and worldwide.