The US Food and Drug Administration (FDA) has amended the emergency use authorisations (EUAs) for the Johnson & Johnson and Moderna COVID-19 vaccines, allowing for the use of a single booster dose.

For the Moderna vaccine, the FDA has approved a single booster dose to be administered at least six months after completion of the first doses in individuals aged 65 years and older, as well as individuals aged 18-64 years old who are at high risk of severe COVID-19 or with frequent ‘institutional or occupational’ exposure to the virus.

A single booster does of the J&J vaccine has been approved at least two months following the first single-dose primary regimen for individuals aged 18 years and older.

“The amendments to the emergency use authorisations to include a single booster dose in eligible populations are based on the available data and information and follows the input from the members of our advisory committee who were supportive of the use of a booster dose of these vaccines in eligible populations,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research.

“We are also taking action today to include the use of mix and match boosters to address this public health need. We will work to accrue additional data as quickly as possible to further assess the benefits and risks of the use of booster doses in additional populations and plan to update the healthcare community and public with our determination in the coming weeks,” he added.