Merck & Co said that its experimental Covid-19 pill reduced hospitalisations and deaths by half in people recently infected with the coronavirus and that it would soon ask health officials in the US and around the world to authorise its use.

If cleared, Merck's drug would be the first pill shown to treat Covid-19, a potentially major advance in efforts to fight the pandemic. All Covid-19 therapies now authorised in the US require an IV or injection.