- Britain is rolling out urgent polio vaccinations for all London-based children under 10 as a reemergence of the virus stoked fears of a wider outbreak.
- The immunization campaign is aimed at providing a "high level of protection from paralysis" and limiting further spread of the virus, health officials said.
- It comes after an unvaccinated man from New York City was paralyzed last month after contracting the virus.
Britain is rolling out urgent polio vaccinations for all London-based children under 10 as a reemergence of the virus across the U.K., U.S. and Israel stoked fears of a wider outbreak.
The immunization campaign is aimed at providing a "high level of protection from paralysis" and limiting further spread of the virus, U.K. health authorities said Wednesday.
"All children aged 1 to 9 years in London need to have a dose of polio vaccine now — whether it's an extra booster dose or just to catch up with their routine vaccinations," Dr. Vanessa Saliba, consultant epidemiologist at the U.K.'s Health Security Agency, said.
"It will ensure a high level of protection from paralysis. This may also help stop the virus spreading further," she added.
Parents and carers in affected areas will be contacted by their health practitioner to schedule an appointment for their child to receive an inactivated polio vaccine, with up to a million children expected to be offered the shot.
David Heymann, professor of infectious disease epidemiology at the London School of Hygiene & Tropical Medicine, said the rollout should act as a "wake-up call" for those who are unvaccinated.
"This should give us all a wake-up call – vaccine-derived polio virus is circulating in many countries around the world – including in parts of the U.K. and the U.S.," he said.
"Though not all children and adults who are infected with a vaccine-derived polio virus become paralyzed, those who have not been fully vaccinated are at risk of being paralyzed – and they are also the persons who continue to facilitate transmission and the outbreaks that are occurring in the U.K.," he added.
It comes after an unvaccinated man from New York City was paralyzed last month after contracting the virus.
The city's first known case in a decade left officials warning it could be just "the tip of the iceberg," with hundreds more infections possibly going undetected.
Polio is a rare but highly infectious virus that can occasionally cause serious illness, such as paralysis, in people who are not fully vaccinated.
No cases of polio have been detected in the U.K. since it was eradicated in 2003 following a widespread immunization campaign, and health officials say the risk to the majority of people who are fully vaccinated remains low.
However, British authorities declared a national incident in June after traces of the virus were discovered in sewage samples across several London boroughs.
Routine sewage surveillance in the U.K. usually picks up traces of the virus once or twice a year, typically deriving from individuals who have been vaccinated overseas with the live oral polio vaccine as opposed to the dead version used in the U.K.
But since Feb. 2022, 116 samples of type 2 poliovirus have been detected in samples across eight London boroughs in the north and east of the capital.
The UKHSA said genetic analysis of the samples suggests that the spread has now gone "beyond a close network of a few individuals" and could be spreading within the community. While most of the samples detected are the safe vaccine form of polio, "a few" have mutated enough to be dangerous, it added.
Health officials are now increasing sewage surveillance nationally and investigating the connection between U.K. samples and recent cases detected in the U.S. and Jerusalem, Israel.
"Further investigation is needed to fully understand how they are connected, but it does illustrate that this virus has the potential to cause disease, especially in poorly vaccinated communities," said Dr. Kathleen O'Reilly, associate professor in statistics for infectious disease and expert in polio eradication, London School of Hygiene & Tropical Medicine.