Vaccination is our best defense against COVID-19. 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. Some vaccine breakthrough cases are expected, but getting the vaccine significantly reduces the chances of severe illness if an infection does occur.
If you received the Pfizer primary series vaccine 5 or more months ago, you should receive a booster dose to be as protected as possible against COVID-19. A second booster dose is not recommended at this time.