Pfizer’s CEO tested positive for COVID-19 and is experiencing “very mild symptoms,” he announced Monday.

“I would like to inform the public that I have tested positive for COVID-19,” the biopharmaceutical company’s chairman and CEO, Albert Bourla, said in a statement.

Bourla said he was isolating in place and following all public health precautions.

“I am thankful to have received four doses of the Pfizer-BioNTech vaccine, and I am feeling well while experiencing very mild symptoms,” Bourla also posted on Twitter. “(I) have started a course of Paxlovid.” Paxlovid is not approved, according to Pfizer, but is authorized for emergency use by the FDA to treat mild-to-moderate COVID-19 in high-risk patients age 12 and older, weighing at least 88 pounds, with positive results of SARS-CoV-2 viral testing.

For more information on Paxlovid, visit https://www.covid19oralrx.com/en.