A vial of the COVID-19 vaccine developed by Pfizer and BioNTech that was used at the Royal Victoria Hospital in Belfast, U.K., on Tuesday.

A vial of the Covid-19 vaccine developed by Pfizer Inc. and BioNTech SE ahead of being administered at the Royal Victoria Hospital in Belfast, U.K., on Tuesday, Dec. 8, 2020. The vaccine shots, created by Pfizer Inc. and BioNTech SE, have been made available to 50 hospital hubs around the country, before being distributed to doctor-run vaccination centers that will administer the jabs. Photographer: Liam McBurney/PA Wire/Bloomberg via Getty Images