If the incorrect formulation is administered Resulting in a higher-than-authorized dose: Do not repeat dose. Resulting in a lower-than-authorized dose: Repeat the dose immediately (no minimum interval) with the age-appropriate dose and formulation. Some experts suggest delaying the repeat dose for 8 weeks after the invalid dose based on the potential for increased reactogenicity and the rare risk of myocarditis and pericarditis associated with Moderna, Novavax, and Pfizer-BioNTech vaccines, especially in males ages 12-39 years. See Considerations for extended intervals for COVID-19 vaccine primary series. If a person moves from a younger age group to an older age group during the primary series or between the primary series and booster dose, they should receive the vaccine dosage for the older age group for all subsequent doses. However, FDA allows the formulation for either age group to be administered for certain age transitions. See Moderna COVID-19 Vaccine for Children who Transition from a Younger to Older Age Group, Pfizer-BioNTech for Children who Transition from a Younger to Older Age Group, and the product-specific EUA for more information.