In line with CEO Albert Bourla, Pfizer’s Covid capsule could possibly be obtainable at house by the tip of the 12 months

Pfizer’s experimental oral drug to treat Covid-19 at the first sign of illness could be available by the end of the year, CEO Albert Bourla told CNBC on Tuesday.

The company, which worked with German drug maker BioNTech to develop the first approved Covid-19 vaccine in the United States, started an early clinical trial in March testing a new antiviral therapy for the disease. The drug belongs to a class of drugs called protease inhibitors, and it works by blocking an enzyme that the virus needs to replicate in human cells.

Protease inhibitors are used to treat other viral pathogens such as HIV and hepatitis C.

If the clinical trials go well and the Food and Drug Administration approves it, the drug could be distributed in the US by the end of the year, Bourla told CNBC’s Squawk Box.

Health experts say the drug taken orally could make a change because people newly infected with the virus could use it outside of hospitals. The researchers hope the drugs will prevent the disease from getting worse and prevent hospital stays.

In addition to the drug, Pfizer is also testing its vaccine in 6-month-old to 11-year-old children. Vaccinating children is critical to ending the coronavirus pandemic, say public health officials and infectious disease experts.

Earlier this month, the company asked the FDA to extend their vaccine approval to teenagers ages 12-15 after a study found the shot was 100% effective.

Bourla told CNBC on Tuesday that he was “very optimistic” that the FDA would approve the use of the shot in teenagers.