In a first, Britain okays trial where volunteers will be exposed to virus

Britain became the first country in the world on Wednesday to give the go-ahead for human challenge trials in which volunteers will be deliberately exposed to Covid-19 to advance research into the disease caused by the novel coronavirus.

The trial, due to start within a month, will see up to 90 healthy volunteers aged between 18 and 30 exposed to the smallest amount of the virus needed to cause infection, scientists behind the plans told reporters at a news briefing.

Volunteers will be screened for possible health risks before being allowed to take part, and kept in quarantine for close monitoring by