On Monday, Jan. 3, the Food and Drug Administration expanded eligibility for Pfizer-BioNTech booster shots to children ages 12 to 15 years old, as school restarts after winter break and amid a surge of COVID infections across the country.

The FDA also reduced the time between the second Pfizer dose and the booster shot to five months, down from six. The agency also authorized a third vaccine dose as part of the primary series of shots for children ages five through 11 who have compromised immune systems. 

“The recent rise in COVID-19 cases is concerning to all and today’s decision by the FDA to further expand the Emergency Use Authorization of a booster dose of our vaccine is critical to help us ultimately defeat this pandemic,” Pfizer CEO Albert Bourla said in a statement.

The FDA said peer-reviewed data from multiple labs demonstrated that Pfizer booster doses significantly improve an individual’s antibody response to the Omicron variant. Allowing people to get booster shots a month earlier may provide better protection faster as the variant rapidly spreads, the agency said. 

The FDA said it reached its decision after reviewing data from Israel, which included information on 6,300 people ages 12-15 who received a booster shot at least five months after their initial two-dose vaccination.

"Throughout the pandemic, as the virus that causes COVID-19 has continuously evolved, the need for the FDA to quickly adapt has meant using the best available science to make informed decisions with the health and safety of the American public in mind," acting FDA Commissioner Janet Woodcock, M.D., said in a statement.

Woodcock said it is critical for the public to take "effective, life-saving preventative measures," including booster shots, during the current surge of infections driven by the omicron variant.

The data showed no new cases of two possible side effects that had been observed in some young people who received the vaccine — myocarditis, an inflammation of the heart, and pericarditis, an inflammation of the saclike tissue surrounding the heart. 

For children ages five to 11 who have undergone organ transplantation or have conditions that compromise their immune system will receive three doses to receive the maximum benefit from vaccination.

New COVID infections have hit a pandemic high in the U.S. as the contagious Omicron variant has replaced Delta as the dominant strain.

According to Johns Hopkins University, the U.S. reported a seven-day average of 404,000 new cases as of Sunday, Jan. 2, an increase of 104% compared to the previous week. 

Dr. Rochelle Walensky, director of the U.S. Centers for Disease Control and Prevention, has encouraged everyone who is eligible to receive a booster dose.

The CDC’s panel of advisors is scheduled to meet Wednesday, Jan. 5, to discuss whether the agency should officially recommend the booster shots for kids ages 12 to 15.

It is expected that Walensky will sign off on that recommendation — as well as the guidance to shorten Pfizer's booster doses to five months — ahead of Wednesday's meeting of independent advisors.