Children aged one to 11 in London will be offered polio vaccines as part of a catch-up campaign.
Health officials warned last year that there had been “some transmission” of the virus in the capital after detecting poliovirus in sewage samples.
The UK Health Security Agency (UKHSA) said on Thursday there has been fewer poliovirus detections in London which suggests reduced community transmission but added that vaccine rates in some London boroughs is still too low.
Polio, which was officially eradicated in the UK in 2003, can cause paralysis in rare cases and can be life-threatening.
The World Health Organisation requires evidence of 12 months of zero detections before the UK is no longer considered to be a polio “infected” country.
The UKHSA said 87.6% of children in London are receiving all their polio vaccinations by the time they turn one, compared to 92.1% in England as a whole.
