No. You should administer the second dose as close as possible to the recommended interval after the first dose. However, if the second dose is administered after this interval, there is no need to restart the series. An 8-week interval may be optimal for some people, especially males ages 12–39 years because of the small risk of myocarditis and pericarditis associated with Moderna, Novavax, and Pfizer-BioNTech COVID-19 vaccines. Vaccine effectiveness may also be increased with an interval longer than 3 or 4 weeks. For additional information on the vaccination schedule, see: People who are not moderately or severely immunocompromised People who are moderately or severely immunocompromised Considerations for extended intervals for COVID-19 vaccine primary series