Pfizer CEO says a pill you can take at home to treat COVID could be ready by end of 2021

• Pfizer CEO Albert Bourla said a pill to fight COVID could be ready by the end of 2021.
• Bourla said the antiviral pill, to be taken in the early stages of COVID, would be a "game-changer."
• The pharmaceutical company is now conducting clinical trials and tests for the drug.

A COVID-busting game-changer could be on its way - in the form of a pill you can take to combat the early stages of an infection.

Pfizer CEO Albert Bourla told CNBC on Tuesday that an oral antiviral pill that can be taken in the comfort of one's home is in the works and could be made available to the public by the end of this year.

Bourla said he expected this experimental oral drug would be effective against multiple variants of the virus and be used to treat COVID patients at the onset of the illness, way before they require critical care. He also added that one of the drug's major benefits was saving people trips to the hospital to get treatment for COVID.

The drug, which falls under a class of medicines called protease inhibitors, works like this: it binds to viral enzymes, stopping the virus from replicating in human cells. These inhibitors attack the "spine" of the COVID virus and prevent it from further multiplying in our respiratory system.

Protease inhibitors are also used to treat other illnesses, like HIV and hepatitis C.

"That allows us to believe that will be way more effective against the multiple variants. That's good news, and we are now progressing the studies, and we will have more news around summer," said Bourla.

CNBC wrote that early-stage clinical trials for the drug, currently known as "PF-07321332," have been underway since March.

According to documents seen by the Telegraph, the pharmaceutical company intends to have PF-07321332 be administered to patients in combination with small doses of Ritonavir, an antiviral that is currently being used to treat HIV. Ritonavir will act as a "booster" to increase the amount of PF-07321332 in a patient's bloodstream and make the dose more effective.

The Telegraph also reported that human trials for Pfizer's COVID oral antiviral pill are kicking off. Documents dated Feb. 8 that the publication obtained outlined the company's testing strategy for trial subjects: a 145-day long trial period, with 28 additional days for "screening and dosing."

"The safety of the study drug has been studied in animals. In these animal studies, no significant risks or safety events of concern were identified, and the study drug did not cause side-effects at any of the dose levels that will be used in clinical studies," said the documents.

Bourla also confirmed that Pfizer is continuing vaccine tests on children aged six months to 11 years, and said that he was "very optimistic" that the US FDA will soon approve the use of the Pfizer vaccine in adolescents.