Pfizer has started a global study to explore the efficacy and safety of an oral drug meant to prevent COVID-19, the disease caused by the CCP (Chinese Communist Party) virus. Pfizer’s Phase 2/3 study will evaluate the drug candidate, PF-07321332, in participants who live in the same household as a person who has a confirmed COVID-19 infection. Participants will also receive ritonavir, an antiretroviral typically used to treat HIV and AIDS. The randomized, double-blind, placebo-controlled study will enroll up to 2,660 health adults 18 or older, Pfizer said. Half will be randomly assigned to receive the drug candidate and ritonavir and the other half will get a placebo. Both groups will take medicine or a placebo twice daily for 5 or 10 days. The primary objective is ascertaining whether PF-07321332 is safe and whether it can prevent COVID-19 infection through 14 days following exposure to the CCP virus. “If successful, we believe this …