While mixing doses during a primary series is not recommended at this time, there is no evidence that shows any harm from getting different COVID-19 vaccines. You may choose to receive a different vaccine for your booster shot if you have completed a primary series and are eligible for a booster. CDC’s recommendations allow for this type of mix and match dosing for booster shots.
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. 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. Children in this age group who previously received 3 monovalent Pfizer primary series doses are eligible to receive 1 bivalent Pfizer booster dose at least 2 months after completion of the monovalent primary series.
The monovalent Novavax booster and the Johnson & Johnson primary and booster vaccinations are authorized for people 18 and older in limited situations.
Some people may have a preference for the vaccine type that they originally received, and others may prefer to get a different booster.