Vaccination drive enters new phase in U.S. and Britain

82-year-old Brian Pinker receives the Oxford University/AstraZeneca COVID-19 vaccine from nurse Sam Foster at the Churchill Hospital in Oxford, England, Monday, Jan. 4, 2021. Pinker, a retired maintenance manager received the first injection of the new vaccine developed between Oxford University and drug giant AstraZeneca. (Steve Parsons/Pool Photo via AP)

The first Americans inoculated against COVID-19 began rolling up their sleeves for their second and final dose Monday, while Britain introduced another vaccine on the same day it imposed a new nationwide lockdown against the rapidly surging virus.