Footage issued by Britain’s Oxford University shows a person injected as part of human trials in the U.K. to test a potential coronavirus vaccine last month. Pfizer on Monday began U.S. trials of another vaccine candidate.

Screen grab from video issued by Britain’s Oxford University, showing a person injected as part of human trials in the U.K. to test a potential coronavirus vaccine, last month. Pfizer on Monday began U.S. trials of another vaccine candidate.