Introduction
High rates of COVID-19 vaccination remain far from universal in many high-income countries despite widespread availability of vaccines in most of these countries.
In the USA, data from the Centers for Disease Control and Prevention (CDC) show that 66·7% of people aged 18 years or older had received at least one dose of an authorised COVID-19 vaccine as of July 1, 2021.
By June 1, 2022, 89·3% of people aged 18 years or older had received at least one dose of vaccine.
However, these averages obscure wide geographical variation across the USA in this age group, from 69·7% (in Wyoming) to at least 95% in several states (eg, New York, New Jersey, and Pennsylvania) on June 1, 2022.
For many diseases that are preventable by vaccines, high levels of adult immunity are achieved by policies that promote vaccination during childhood, such as school entry vaccination requirements.
Few vaccines that are specifically targeted for adults receive high levels of uptake. For example, only 50·2% of adults in the USA received an influenza vaccine during the 2020–21 influenza…
