(CNN) The US Food and Drug Administration authorized booster doses of both Covid-19 vaccines made by Moderna and Johnson & Johnson Wednesday and also said any of the three authorized vaccines could be used as a booster in a "mix and match" approach.
The FDA gave emergency use authorization for boosters of Moderna's vaccine for people fully vaccinated at least six months ago who are also at least 65, or who are at least 18 and who are at high risk of severe Covid-19 or have frequent institutional or occupational exposure to SARS-CoV-2.
"The use of a single booster dose of the Janssen (Johnson and Johnson) COVID-19 Vaccine may be administered at least 2 months after completion of the single-dose primary regimen to individuals 18 years of age and older," the FDA added in a statement.
"The use of each of the available COVID-19 vaccines as a heterologous (or 'mix and match') booster dose in eligible individuals following completion of primary vaccination with a different available COVID-19 vaccine," the FDA said.
"To clarify that a single booster dose of the Pfizer-BioNTech COVID-19 Vaccine may be administered at least 6 months after completion of the primary series to individuals 18 through 64 years of age with frequent institutional or occupational exposure to SARS-CoV-2," it added.
"As the pandemic continues to impact the country, science has shown that vaccination continues to be the safest and most effective way to prevent COVID-19, including the most serious consequences of the disease, such as hospitalization and death.
The available data suggest waning immunity in some populations who are fully vaccinated. The availability of these authorized boosters is important for continued protection against COVID-19 disease," FDA Acting Commissioner Dr. Janet Woodcock said in a statement.
"The amendments to the emergency use authorizations 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," added Dr. Peter Marks, director of the FDA's vaccine arm, the 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."
The US Centers for Disease Control and Prevention's vaccine advisers, the Advisory Committee on Immunization Practices, meets Thursday to decide on whether to recommend the FDA's authorization for the Americans people, and then the CDC director will decide whether to sign off on ACIP's guidance.