According to Pfizer's research, the in vitro research so far shows that PF0732 1332 is an effective protease inhibitor, which can inhibit the activity of novel coronavirus. Phase I clinical trials in the United States are currently evaluating the safety and tolerance of drugs in healthy adults. Comb inhibitors can prevent virus replication in cells alone or in combination with other antiviral drugs, and have been proved to be effective against pathogens of other viruses, such as HIV and hepatitis C. The structure and preclinical data of PF0732 1332 will be presented at the spring meeting of American Chemical Society on April 6th. This new drug is the second protease inhibitor in clinical trials in Pfizer. Another Pfizer protease inhibitor, PF073048 14, was given intravenously and is currently undergoing clinical trials on hospitalized patients.