London: British Prime Minister Boris Johnson watches as nurse Rebecca Cathersides administers the Pfizer-BioNTech COVID-19 vaccine to Lyn Wheeler at Guy's Hospital in London, Tuesday, Dec. 8, 2020. U.K. health authorities rolled out the first doses of a widely tested and independently reviewed COVID-19 vaccine Tuesday, starting a global immunization program that is expected to gain momentum as more serums win approval. AP/PTI
.jpg)
