Pfizer CEO Albert Bourla said Monday he expects the company’s Covid-19 treatment pill to be effective against the omicron variant of the virus causes Covid-19.

“The good news when it comes to our treatment, it was designed with that in mind, it was designed with the fact that most mutations are coming in the spikes,” Bourla told CNBC’s “Squawk Box.” “So that gives me very high level of confidence that the treatment will not be affected, our oral treatment will not be affected by this virus.”

Pfizer submitted its application earlier this month to the Food and Drug Administration to authorize the pill, Paxlovid, for emergency use. In a clinical trial of people age 18 and over, Pfizer found the pill reduces hospitalization and death by 89% when taken with a widely used HIV drug within three days of the start of symptoms.