In a July 30, 2020, photo, Kai Hu, a research associate transfers medium to cells, in the laboratory at Imperial College in London. Imperial College is working on the development of a COVID-19 vaccine. In a report to Congress and an accompanying “playbook” for states and localities, key federal health agencies and the Defense Department sketched out complex plans for a vaccination campaign to begin gradually early next year or later in 2020, eventually ramping up to reach any American who wants a shot. The Pentagon is involved with the distribution of vaccines, but civilian health workers will be the ones giving shots. (AP Photo/Kirsty Wigglesworth)