Bourla said that for high-income countries, Pfizer expected to price its treatment close to where Merck has priced its own Covid-19 pill.

Merck’s US contract price is around US$700 for a five-day course of therapy.

For low-income countries, Bourla said Pfizer was considering several options, with the goal of “no barrier for them as well to have access”.

Pfizer’s trial results suggested its oral drug surpassed Merck’s pill, molnupiravir, which was shown last month to halve the risk of dying or being hospitalised for Covid-19 patients at high risk of serious illness.

Paxlovid could secure US regulatory approval by the end of the year. The Pfizer trial was stopped early due to its high success rate. Full trial data is not yet available from either company.

“If authorised by the FDA, we may soon have pills that treat the virus in those who become infected,” Biden said. “The therapy would be another tool in our toolbox to protect people from the worst outcomes of Covid-19.”

Pfizer’s pill is given in combination with an older antiviral called ritonavir. The treatment consists of three pills given twice daily. It has been in development for nearly two years.

The company said it expected to manufacture 180,000 treatment courses by the end of this year, and at least 50 million courses by the end of next year, including 21 million in the first half of 2022.

Bourla said that, based on the better-than-expected trial results, Pfizer was considering potentially doubling next year’s manufacturing target.

The Pfizer and Merck pills are eagerly anticipated, with only limited options currently available for treating people sick with Covid-19.

Merck’s pill was approved by British regulators on Thursday. On Friday, the company told Bloomberg it was working with Chinese regulators to explore the possibility of bringing its Covid-19 pill to China.

Even with the potential offered by the Pfizer and Merck pills, preventing Covid-19 infections through broad use of vaccines remains the best way to control a pandemic that has killed more than 5 million people worldwide, including more than 750,000 in the US, according to infectious disease experts.

“Vaccines are going to be the most effective and reliable tool that we have in this pandemic,” said Dr Grace Lee, professor of paediatrics at Stanford University School of Medicine. “These oral medications are going to augment our ability to really reduce the risk of severe disease, hospitalisation and death, which is huge, but it won’t prevent infection.”

While more than 7 billion vaccine doses have been administered worldwide, that has covered only about half the world’s people. In the US, 58 per cent of all people, including 70 per cent of adults, are fully vaccinated. There are more than 400,000 new Covid-19 cases daily worldwide, with infections rising in 50 countries.

Mizuho analyst Vamil Divan forecast a “very minor impact” from the Pfizer drug on vaccination among people who do not want the vaccine or a booster shot as recommended by US health regulators.

“I think there’s a small percentage of people that may decide not to get vaccinated, now that there are good treatment options,” Divan said.

Pfizer said it plans to submit interim trial results for its pill to the Food and Drug Administration (FDA) before the US Thanksgiving holiday on November 25.