The World Health Organisation (Who ) has declared a national emergency as several samples of live vaccine-derived polio have been found circulating in London sewage systems. It is believed that the detected strain originated from an individual Who was vaccinated with the live oral polio vaccine abroad. If this strain continues to circulate, it can mutate into vaccine-derived polio, which could cause significant morbidity and mortality in unvaccinated children.
With this in mind, the Joint Committee on Vaccination and Immunisation (JCVI) has advised that a targeted inactivated polio vaccine (IPV) booster dose should be offered to all children aged one to nine years across London. If engagement with the booster campaign is high, herd immunity will be met in areas with low vaccine coverage and there will likely be no cases of polio in the UK. If engagement remains low, however, the poliovirus will continue to circulate and there could be a re-emergence of polio within, and potentially outside, London.