The US Centers for Disease Control and Prevention (CDC) on Tuesday backed its week-old guidance for people seeking to end their Covid-19 isolation at five days, adding they could take a rapid antigen test if they want to and can access one, but is not requiring that.

The agency had been pressured by health experts to institute a test requirement after it cut in half its guidance last week for people to isolate after a Covid-19 infection to five days from 10. It said the move was based on the science around the transmission of the virus.

On Tuesday, the CDC added an...