CDC Updates Guidance on Timing for Pfizer and Moderna Primary Series

This week the Centers for Disease Control and Prevention (CDC) added considerations for an 8-week interval between the first and second doses of a primary mRNA vaccine schedule for some patients.

They added the following language to their Interim Clinical Considerations for Use of COVID-19 Vaccines Currently Approved or Authorized in the United States webpage:


An 8-week interval may be optimal for some people ages 12 years and older, especially for males ages 12 to 39 years. A shorter interval (3 weeks for Pfizer-BioNTech; 4 weeks for Moderna) between the first and second doses remains the recommended interval for: people who are moderately to severely immunocompromised; adults ages 65 years and older; and others who need rapid protection due to increased concern about community transmission or risk of severe disease.


The webpage contains more details. It also links to Guidance for COVID-19 vaccination for people who are moderately or severely immunocompromised (and require a 3-dose primary series).