The FDA has authorized a second booster vaccine from both Moderna and Pfizer/BioNTech for US adults age 50 and older, and certain immunocompromised patients.

Adults over 50 who have previously received a first booster of any authorized COVID-19 vaccine are eligible to receive the additional shot, at least four months after the initial booster.

The FDA also authorized the second booster of Pfizer/BioNTech is immunocompromised patients age 12 and older, and the Moderna second booster in immunocompromised patients age 18 and older.

“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,” said Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research. “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. So, those who have not received their initial dose are strongly encouraged to do so.”

Moderna Booster

A second booster dose of Moderna’s COVID-19 vaccine (mRNA-1273) at the 50 µg dose level in adults 50 years of age and older who have received an initial booster of any of the authorized or approved COVID-19 vaccines and adults 18 years of age and older with certain kinds of immunocompromise.

“The FDA’s endorsement of a second booster dose will allow millions of Americans to build and maintain protection against SARS-CoV-2,” said Stéphane Bancel, Chief Executive Officer of Moderna. “The virus continues to evolve, and we are currently on the verge of another potential wave driven by the BA.2 variant. Data continue to show that mRNA boosters remain the best defense against severe infection and death, and vaccines are a foundational part of our public health protection.”


The second booster of the Pfizer/BioNTech vaccine was authorized in adults ages 50 years and older who have previously received a first booster of any authorized COVID-19 vaccine. The FDA also has authorized it for individuals 12 years of age and older who have been determined to have certain kinds of immunocompromise and who have received a first dose, Pfizer reports.

The additional dose is to be administered at least four months after the first and is the same formulation and strength as prior Pfizer-BioNTech COVID-19 vaccine doses.