The NHS is to contact parents of children under the age of five in London who are not up-to-date with their polio vaccinations to invite them to take up the jab.
In the UK, the polio vaccine is given as part of the NHS routine childhood vaccination schedule at 8, 12 and 16 weeks old. At three years and four months old children are given a booster and again at age 14.
The message comes after the UK Health Safety Agency (UKHSA), working with the Medicines & Healthcare products Regulatory Agency (MHRA), found poliovirus in sewage samples collected from the London Beckton Sewage Treatment Works.
Investigations are underway after several closely related viruses were found in sewage samples taken between February and May. The virus is now classified as a vaccine-derived poliovirus type 2 (VDPV2), which on rare occasions can cause serious illness, such as paralysis, in people who are not fully vaccinated.
According to the UKHSA, as part of routine surveillance, it is normal for one to three ‘vaccine-like’ polioviruses to be detected each year, but they have always been one-off findings that were not detected again. It says these previous detections occurred when an individual vaccinated overseas with the live oral polio vaccine returned or travelled to the UK and briefly ‘shed’ traces of the vaccine-like poliovirus in their faeces.
It is thought that the detection of a VDPV2 suggests ‘it is likely’ there has been some spread between closely linked individuals in North-East London who are now ‘shedding’ the type 2 strain of poliovirus.
The UKHSA is now investigating whether any community transmission of the virus is occurring, however it says there have been not reported of associated cases of paralysis and says that the risk to the public is low.
The UK continues to be considered by the World Health Organisation (WHO) to be polio-free with low-risk for transmission due to the high level of vaccine coverage. However, vaccine coverage for childhood vaccines has decreased nationally and especially in parts of London over the past few years so the UKHSA is urging people to check they are up-to-date with their vaccines.
The UK was declared polio free in 2003.
Dr Vanessa Saliba, consultant epidemiologist at UKHSA, said, ‘Vaccine-derived poliovirus is rare and the risk to the public overall is extremely low.
‘Vaccine-derived poliovirus has the potential to spread, particularly in communities where vaccine uptake is lower. On rare occasions it can cause paralysis in people who are not fully vaccinated so if you or your child are not up to date with your polio vaccinations it’s important you contact your GP to catch up or if unsure check your red book. Most of the UK population will be protected from vaccination in childhood, but in some communities with low vaccine coverage, individuals may remain at risk.
‘We are urgently investigating to better understand the extent of this transmission and the NHS has been asked to swiftly report any suspected cases to the UKHSA, though no cases have been reported or confirmed so far.’
Jane Clegg, chief nurse for the NHS in London, added, ‘The majority of Londoners are fully protected against Polio and won’t need to take any further action, but the NHS will begin reaching out to parents of children aged under five in London who are not up-to-date with their Polio vaccinations to invite them to get protected.
‘Meanwhile, parents can also check their child’s vaccination status in their Red Book and people should contact their GP Practice to book a vaccination should they or their child not be fully up-to-date.’
