Population Immunity Against COVID-19 in the United States.

Background null As of 28 July 2021, 60% of adults in the United States had been fully vaccinated against COVID-19, and more than 34 million cases had been reported. Given the uncertainty regarding undocumented infections, the population level of immunity against COVID-19 in the United States remains undetermined. null Objective null To estimate the population immunity, defined as the proportion of the population that is protected against...