Clinical trials and observational studies show that all COVID-19 vaccines authorized in the United States are effective at preventing COVID-19, especially severe disease, hospitalization, and death. For primary and booster vaccination, people should receive an age-appropriate mRNA vaccine (Pfizer or Moderna). The Johnson & Johnson vaccine is authorized for anyone age 18 and older if no other approved vaccine is available.

See additional recommendations for people who are moderately to severely immunocompromised. A second booster dose is recommended for certain people at increased risk of severe disease.