Herd immunity could develop from just 43% of people catching Covid-19, scientists claim

Government scientists floated the idea at the start of the UK's outbreak, with the 'delay' stage of its original plan based on allowing the virus to spread slowly. But experts warned that half a million people could die if the country didn't go into lockdown to stop the virus in its tracks, and officials have since denied that aiming for herd immunity — which could have seen 40million people allowed to be infected — was ever the plan. The study hinges on people only being able to catch the virus once, then becoming immune to it in future — but scientists still haven't worked out whether this is true.