Some Americans Shouldn’t Get Another COVID-19 Vaccine Shot, FDA Says

A college student gets a COVID-19 vaccine at the California State University–Long Beach in Long Beach, Calif., on Aug. 11, 2021. Patrick T. Fallon/AFP via Getty Images

Some Americans cannot receive another COVID-19 vaccine dose, U.S. regulators said on April 18, as they made sweeping changes to the vaccine system.

The U.S. Food and Drug Administration (FDA) announced the changes, including replacing the old Pfizer and Moderna vaccines with updated bivalent shots that had previously only been available as boosters.