Linus Chua, Bloomberg News A healthcare worker administers a dose of the Pfizer-BioNTech Covid-19 Vaccine at a mass vaccination site at The Forum arena in Inglewood, California, U.S., on Friday, Feb. 26, 2021. U.S. hospitalizations for the coronavirus have plunged 56% from a mid-January peak as the number of patients exiting California hospitals accelerated, data from the Department of Health and Human Services show. Photographer: Eric Thayer/Bloomberg , Bloomberg (Bloomberg) -- Los Angeles Countyâs top health official said fully vaccinated people made up one-in-five Covid-19 infections in June and warned that the figure may rise in July with a higher level of community transmission.