The Food and Drug Administration (FDA) has updated the Emergency Use Authorization (EUA) for the Moderna COVID-19 vaccine to allow for the administration of a single booster dose in individuals 18 years of age and older at least 5 months after completion of the primary series. Previously, the interval between the primary series and the booster had been 6 months.

The updated EUA follows a similar decision the Agency made with the Pfizer-BioNTech COVID-19 vaccine. “The country is in the middle of a wave of the highly contagious Omicron variant, which spreads more rapidly than the original SARS-CoV-2 virus and other variants that have emerged,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research. “Vaccination is our best defense against COVID-19, including the circulating variants, and shortening the length of time between completion of a primary series and a booster dose may help reduce waning immunity.” 

The most common adverse reactions reported following a booster dose of the Moderna COVID-19 vaccine were pain, redness, swelling at the injection site, fatigue, headache, muscle or joint pain and chills.

Updated fact sheets for the Moderna COVID-19 Vaccine are available here.


Coronavirus (COVID-19) update: FDA shortens interval for booster dose of Moderna COVID-19 vaccine to five months. News release. US Food and Drug Administration. Accessed January 7, 2022.