The CDC recommends people 6 months and older receive an age-appropriate, updated mRNA booster dose if at least 2 months have passed since their primary series or since their most recent booster dose. Eligible individuals can get either the Pfizer or Moderna updated booster, regardless of whether their primary series or most recent dose was with Pfizer, Moderna, Novavax, or the Johnson & Johnson vaccine.
For children age 6 months to 4 years who get the Pfizer primary series, the updated bivalent vaccine will be used as the third dose in the series, rather than as a separate booster. Use CDC’s COVID-19 vaccination schedule, or answer a few questions on the CDC website to make sure you are up to date.