Johnson & Johnson single dose Covid vaccine cleared by US officials

(PA)

The US is getting a third vaccine to prevent Covid-19, as the Food and Drug Administration cleared a Johnson & Johnson shot that works with just one dose instead of two.

Health experts are anxiously awaiting a one-and-done option to help speed vaccinations, as they race against a virus that already has killed more than 510,000 people in the US and is mutating in increasingly worrisome ways.