The United States has authorised Pfizer Inc's antiviral Covid-19 pill for people ages 12 and older at risk of severe illness, the first oral and at-home treatment as well as a new tool against the fast-spreading Omicron variant, Reuters reports.

Pfizer raised its 2022 production projections to 120 million courses of treatment from 80m and said it was ready to start immediate delivery in the United States. The treatment's two-drug regimen includes a new medicine and a second older antiviral called ritonavir.

The US government will have 265,000 treatment courses available by January and supply will ramp up in subsequent months, White House Covid-19 response coordinator Jeff Zients told a briefing. The government expects to receive the 10m courses it has ordered within six months.

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