Drugmaker Pfizer said Nov. 5 that its experimental antiviral pill slashes the chances of hospitalization or death in high-risk adults from COVID-19 by 89%.
The results far surpass the 50% effectiveness of a similar pill from New Jersey-based pharmaceutical company Merck, whose data is also being reviewed by federal regulators.
Pfizer, in the Friday morning announcement, said it will submit its findings to the U.S. Food and Drug Administration for emergency approval “as soon as possible.”
It’s one of three drugmakers – the other two being Moderna and Johnson & Johnson – who have been supplying the globe with the COVID-19 vaccine. And, only Pfizer has been approved in the United States for a vaccine that can be given to children as young as 5 years of age.
“Today’s news is a real game-changer in the global efforts to halt the devastation of this pandemic,” reads a Friday morning prepared statement from Albert Bourla, Pfizer’s chairman and chief executive officer.

The Pfizer vaccine is one of three available in the U.S.. – U.S AIR FORCE PHOTO/STAFF SGT. PAOLO FELICITAS
Public health officials have stressed that the new pills – be it the Merck or Pfizer version – would be a novel and effective means of preventing serious cases of COVID-19, but note that the vaccine is still king in terms of prevention.
The pill is known as PF-07321332; it’s orally ingested in combination with a low dose of an anti-HIV pill called ritonavir. Combined, Pfizer’s “PAXLOVID” treatment works by blocking a type of enzyme called a protease, which the coronavirus needs in order to replicate itself.
Pfizer’s data relies on 1,219 adult participants who had a laboratory-confirmed infection of COVID-19 within the last five days and showed mild to moderate symptoms. They also needed to have displayed at least one symptom of an underlying medical condition that increased the risk of a severe COVID-19 infection.
After 28 days taking part in the treatment, six out of the 607 participants were hospitalized with no deaths, while in the 612-person group that took the placebo, 41 were hospitalized and 10 of them died.
“These data suggest that our oral antiviral candidate, if approved or authorized by regulatory authorities, has the potential to save patients’ lives, reduce the severity of COVID-19 infections, and eliminate up to nine out of ten hospitalizations,” Bourla continued.