Children aged one to 11 will receive jabs after traces of the virus were found in London.
Four African countries have reported new cases of polio linked to the oral vaccine, as global health numbers show there are now more children being paralyzed by viruses originating in vaccines than in the wild. In a report late last week, the World Health Organization and partners noted nine new polio cases caused by the vaccine in Nigeria, Congo, Central African Republic and Angola. Seven countries elsewhere in Africa have similar outbreaks and cases have been reported in Asia, including the two countries where polio remains endemic, Afghanistan and Pakistan.
Donor governments and philanthropists pledged $2.6 billion on Tuesday to help fund a worldwide polio eradication plan that has taken decades to reach what global health specialists say is now the "last mile".