FILE - Albert Bourla, chief executive officer of Pfizer, speaks at a Press Conference on Pfizer and Partners Announce Accord for a Healthier World at the 51st annual meeting of the World Economic Forum, WEF, in Davos, Switzerland, Wednesday, May 25, 2022. The top executive at Pfizer, a leading producer of COVID-19 vaccines, has tested positive for the virus and said he is experiencing very mild symptoms. He said Monday, Aug. 15, 2022, that he started taking Pfizer’s Paxlovid pill treatment and is isolating while he recovers. (Gian Ehrenzeller/Keystone via AP, File)