|Articles|March 29, 2022

FDA Amends Authorization for Second Booster Dose for mRNA COVID-19 Vaccines

The new action by the federal agency now means the additional booster shot can be administered to people 50 years and older.


The Food and Drug Administration (FDA) has amended its Emergency Use Authorizations (EUA) for both mRNA vaccines to now include a second booster dose allowing adults 50 years and older the ability to receive the additional shot. 

The federal agency says this action now makes a second booster dose available to populations at higher risk for severe disease, hospitalization, and death. 

FDA amended the EUAs as follows: 

  • A second booster dose of the Pfizer-BioNTech COVID-19 Vaccine or Moderna COVID-19 Vaccine may be administered to individuals 50 years of age and older at least 4 months after receipt of a first booster dose of any authorized or approved COVID-19 vaccine.
  • A second booster dose of the Pfizer-BioNTech COVID-19 Vaccine may be administered to individuals 12 years of age and older with certain kinds of immunocompromise at least 4 months after receipt of a first booster dose of any authorized or approved COVID-19 vaccine. These are people who have undergone solid organ transplantation, or who are living with conditions that are considered to have an equivalent level of immunocompromise.
  • A second booster dose of the Moderna COVID-19 Vaccine may be administered at least 4 months after the first booster dose of any authorized or approved COVID-19 vaccine to individuals 18 years of age and older with the same certain kinds of immunocompromise.

"Current evidence suggests some waning of protection over time against serious outcomes from COVID-19 in older and immunocompromised individuals. Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals,” Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, said in a statement.

FDA made it clear in its statement this is only applicable to the Moderna and Pfizer-BioNTech vaccines, and the agency also reiterated the recommendation to get a booster shot for those who have not had one yet.

“Additionally, the data show that an initial booster dose is critical in helping to protect all adults from the potentially severe outcomes of COVID-19,” Marks also stated. “So, those who have not received their initial booster dose are strongly encouraged to do so.”


Related to this article

NFID Survey Finds Respiratory Vaccine Gap Driven by Lack of Clarity, Not Hesitancy
The National Foundation for Infectious Diseases (NFID) recently held its respiratory season kick-off, which included the release of its annual respiratory disease survey. This year, the survey revealed the gap between vaccine support and uptake. Robert Hopkins Jr, MD, medical director of NFID delves deeper into the findings of the survey and the vaccine uptake challenges associated with certain immunizations.
Measles Update: October 9, 2026
The latest CDC numbers show a 5.0% increase of measles cases from week-to-week. The US total reached 4080 confirmed cases, 78% above all of 2025.
FAQ: Measles
With US measles cases nearing 3,900 this year and Pennsylvania reporting its fifth measles-related death, here is a review of how the virus spreads, how it is prevented and managed, and what severe disease looks like.
Asymptomatic C difficile Colonization in Infants Doesn’t Mean Benign
A new study in infants challenges the long-standing belief about the pathogen’s effects in the youngest pediatric population. Senior author Joseph Zackular, PhD, provides insights around his work including how it reshapes gut development and offers potential intervention strategies to shield neonates.