Pfizer (NYSE:PFE) revealed that its COVID-19 drug Paxlovid retained in vitro efficacy against the omicron SARS-CoV-2 variant.

The company said that the research indicates that the drug can potentially maintain plasma concentrates “many-fold” times higher than the level needed to prevent replication of the highly transmissible variant.

“These data suggest that our oral COVID-19 therapy can be an important and effective tool in our continued battle against this devastating virus and current variants of concern,” said Dr. Mikael Dolsten, chief scientific officer at Pfizer, in a statement.

Demand for Paxlovid, which FDA authorized in late December, has far exceeded supply.

In January, the White House announced that the federal government would buy 20 million courses of Paxlovid — twice as much as initially planned.

Paxlovid combines two antivirals — nirmatrelvir and ritonavir.

In November 2021, Pfizer also announced a license agreement with the Medicines Patent Pool to authorize the distribution of Paxlovid to close to 100 countries.

A recent feature in Chemical & Engineering News noted that Paxlovid went from initial idea to first clinical trial within 12 months.

In December 2021, the company revealed that the drug reduced hospitalization or death by 89% when administered within three days of symptom onset in a Phase 2/3 study. Administering the antiviral cocktail within five days of symptom onset was 88% efficacious.

Early data from Israel suggests that more than 90% of people infected with COVID-19 improve, according to The Jerusalem Post.