Question: Some of our nonmedical staff initially refused the COVID-19 vaccination but now want it, so I’m trying to help them schedule. Are the days between doses of the mRNA vaccine super important? Delaware Subscriber Answer: Not exactly. The specificity of the COVID-19 mRNA vaccination schedule is mostly due to the way the initial studies were designed, explained Sara Oliver, MD, Lieutenant Commander in the U.S. Public Health Service and co-lead of the Advisory Committee for Immunization Practices COVID-19 Vaccines Work Group for the Centers for Disease Control and Prevention (CDC) COVID-19 Response, in a Clinician Outreach and Communication Activity call concerning the available COVID-19 vaccinations.
The recommendation for the two-dose Pfizer mRA vaccine is 21 days between doses, and 28 days between doses of the Moderna vaccine. The clinical trials suggested that a four-day grace period is OK, but there is no maximum interval between the first and second doses. “If there is a delay in receiving the second dose, they should receive the second dose as soon as possible after that kind of 21- or 28-day interval. You do not have to start the series over again. At this point, there’s no recommendation where we restart the series or need to repeat doses. A person receives two doses of these vaccines, especially in the setting of limited supply. That is what is recommended right now,” Oliver said. The Johnson & Johnson vaccination only requires one dose.