FILE - In this Tuesday, Dec. 8, 2020 file photo, a nurse holds a phial of the Pfizer-BioNTech COVID-19 vaccine at Guy's Hospital in London. As Canadians, Britons and Americans begin getting immunized with a German-developed vaccine against the coronavirus, pressure is building on the European Medicines Agency to approve the shot made by Pfizer Inc. and German company BioNTech. Those countries all approved the COVID-19 vaccine under emergency use rules, meaning it is an unlicensed product. But the EMA approval process for coronavirus vaccines is largely similar to the standard licensing procedure that would be granted to any new vaccine, only on an accelerated schedule. (AP Photo/Frank Augstein, Pool, File)

FILE - In this Monday, DEC. 14, 2020 file photo, the first doses of the Pfizer-BioNTech COVID-19 vaccine are delivered to the Maimonides CHSLD, in Montreal, Canada. As Canadians, Britons and Americans begin getting immunized with a German-developed vaccine against the coronavirus, pressure is building on the European Medicines Agency to approve the shot made by Pfizer Inc. and German company BioNTech. Those countries all approved the COVID-19 vaccine under emergency use rules, meaning it is an unlicensed product. But the EMA approval process for coronavirus vaccines is largely similar to the standard licensing procedure that would be granted to any new vaccine, only on an accelerated schedule. (Ryan Remiorz/The Canadian Press via AP, File)

FILE - In this Tuesday, Dec. 8, 2020 file photo, 90 year old Margaret Keenan, the first patient in the UK to receive the Pfizer-BioNTech COVID-19 vaccine, administered by nurse May Parsons at University Hospital, Coventry, England. As Canadians, Britons and Americans begin getting immunized with a German-developed vaccine against the coronavirus, pressure is building on the European Medicines Agency to approve the shot made by Pfizer Inc. and German company BioNTech. Those countries all approved the COVID-19 vaccine under emergency use rules, meaning it is an unlicensed product. But the EMA approval process for coronavirus vaccines is largely similar to the standard licensing procedure that would be granted to any new vaccine, only on an accelerated schedule. (Jacob King/Pool via AP, File)

FILE - In this Monday, Dec. 14, 2020 file photo, Sandra Lindsay, left, a nurse at Long Island Jewish Medical Center, is inoculated with the Pfizer-BioNTech COVID-19 vaccine by Dr. Michelle Chester, Monday, Dec. 14, 2020, in the Queens borough of New York. (AP Photo/Mark Lennihan, Pool. File)