Polio may be spreading in Britain for first time in 40 YEARS: Strain of paralysis-causing virus mutated from vaccine is 'likely' being transmitted in London as health chiefs declare 'national incident'
Officials have found traces of a vaccine-derived poliovirus in sewage samples in North and East London
Thought that someone vaccinated with live vaccine shed part of virus and spread it to unvaccinated people
Parents are being urged to ensure their children's vaccinations are up to date, particularly after the pandemic
Officials said risk to public 'extremely low' with one in 100 chance of paralysis and high vaccine uptake
Can I take the polio vaccine if I missed out as a child? What are the virus’ symptoms? How many people are infected in the UK? Read our in-depth Q&Ahere