Public health officials have declared a national event and issued a nationwide appeal for parents to ensure their children are vaccinated after multiple samples of vaccine-derived poliovirus were found during routine London sewage testing. are updated.
According to the UK Health Security Agency (UKHSA), several closely related viruses were found in samples taken in north and east London between February and May. The findings suggest some prevalence among closely related individuals.
The virus continues to evolve and is now classified as “vaccine-derived”. poliovirus type 2 (VDPV2), which on rare occasions can cause severe paralysis in people who have not been fully vaccinated.
The health agency is working with other bodies, including the World Health Organization, to investigate the matter urgently to understand the extent of transmission.
“It is important to note that the virus has been isolated only from environmental samples,” the WHO said, adding that “no related cases of paralysis have been detected.”
But it warned, “any form of poliovirus anywhere is a danger to children everywhere.”
The finding is a cause for concern as the last case of wild polio in the UK was in 1984 and the country was declared polio-free in 2003.
risk is low
Health officials, however, have said that the risk of infection with the disease, which causes paralysis in children in less than 1% of cases, is currently low due to high vaccination rates.
“Vaccine-derived poliovirus is rare and the risk to the public as a whole is extremely low,” said Dr Vanessa Saliba, consultant epidemiologist at UKHSA.
“Vaccine-derived poliovirus has the potential to spread, especially in communities where vaccine uptake is low. On rare occasions it can cause paralysis in people who have not been fully vaccinated, so if you or your child is not up to date with polio vaccination it is important that you contact your GP.”
Nationwide vaccination levels are above the 90% needed to contain the outbreak, but coverage rates among London’s under-two have fallen in recent years.
“Most of Londoners are fully protected against polio and will not need to take any further action, but the NHS will begin reaching out to parents of children under five in London to invite them. are not up to date with their polio vaccinations. To be protected,” said chief nurse Jane Clegg for the NHS in London.
The primary polio vaccine course is given to children aged two, three and four months. Three doses are required to complete the primary course. In the UK it is given as part of a six-in-one vaccine.
How did the detection happen?
In the past, the UKHSA said it was discovered when a person had been vaccinated with live oral polio vaccine abroad or returned to or traveled to the country, and shed the virus in their feces for a period of time.
They believe the same has happened this time around, with the main difference being that the virus may have spread even among closely related people.
The agency said the investigation into community transmission was ongoing.
Wastewater monitoring is being expanded to assess the extent of transmission and identify local areas for targeted action.
The UKHSA said health professionals have been alerted to these findings so that they can immediately investigate and report anyone with polio-like symptoms, such as paralysis.