Washington, Sep 23 (IANS): The US Food and Drug Administration (FDA) has authorised booster shots of the Pfizer Covid-19 vaccine for people aged 65 and older or at high-risk.

In a statement late Wednesday, Acting FDA Commissioner Janet Woodcock said: "After considering the totality of the available scientific evidence and the deliberations of our advisory committee of independent, external experts, the FDA amended the EUA (emergency use authorization) for the Pfizer-BioNTech Covid-19 vaccine to allow for a booster dose in certain populations such as health care workers, teachers and day care staff, grocery workers and those in homeless shelters or prisons, among others.

"This pandemic is dynamic and evolving, with new data about vaccine safety and effectiveness becoming available every day.

"As we learn more about the safety and effectiveness of COVID-19 vaccines, including the use of a booster dose, we will continue to evaluate the rapidly changing science and keep the public informed," said Woodcock.

The FDA said boosters were also authorised for people between the ages of 18 through 64 who are at high risk, as well as those "whose frequent institutional or occupational exposure" to the virus puts them at high risk of serious complications from the disease, Xinhua news agency.

The FDA added that booster doses are to be administered at least six months after the completion of the second shot.

On September 17, a panel of experts endorsed offering Pfizer booster shots for those aged 65 and older, and people 16 and over who are at high risk of getting severe Covid-19 or who work in settings that make them more likely to get infected.

Last month, President Joe Biden's administration proposed a plan that would have made all vaccinated Americans eligible for a booster shot eight months after their second shot, or their first in the case of the one-shot Johnson & Johnson vaccine.