On March 29 the U.S. Food and Drug Administration (FDA) and the Centers for Disease Control and Prevention (CDC) approved the use of a second COVID-19 booster shot for adults over age 50 and certain immunocompromised individuals, including heart transplant patients. While not issuing a direct recommendation, the agencies instead issued emergency authorization for a fourth shot of the Pfizer-BioNTech or Moderna vaccines to provide additional protection against the coronavirus and its variants for certain people. The American Heart Association continues to align with guidance from the CDC, the nation’s pandemic control experts, and supports the use of this fourth shot, as indicated.