WASHINGTON -- U.S. regulators on Monday expanded the use of Pfizer's covid-19 vaccine to children as young as 12, offering a way to protect the nation's adolescents before they head back to school in the fall and paving the way for them to return to more normal activities.
Expert advisers to the Centers for Disease Control and Prevention are scheduled to meet Wednesday to issue recommendations for using the two-dose vaccine in 12- to 15-year-olds, and the vaccine can be administered as soon as the CDC director signs off on the recommendation.
Most covid-19 vaccines worldwide have been authorized for adults. Pfizer's vaccine is being used in multiple countries for teens as young as 16, and Canada recently became the first to expand use to 12 and up. Parents, school administrators and public health officials elsewhere have eagerly awaited approval for the shot to be made available to more children.
"This is a watershed moment in our ability to fight back the covid-19 pandemic," Dr. Bill Gruber, a Pfizer senior vice president who's also a pediatrician, told The Associated Press.
The Food and Drug Administration declared that the Pfizer vaccine is safe and offers strong protection for younger teens based on testing of more than 2,000 U.S. volunteers ages 12 to 15. The agency noted there were no cases of covid-19 among fully vaccinated adolescents compared with 16 among youths given dummy shots. More intriguing, researchers found the children developed higher levels of virus-fighting antibodies than earlier studies measured in young adults.
The younger teens received the same vaccine dosage as adults and had the same side effects, mostly sore arms and flu-like fever, chills or aches that signal a revved-up immune system, especially after the second dose.
Pfizer's testing in adolescents "met our rigorous standards," FDA vaccine chief Dr. Peter Marks said. "Having a vaccine authorized for a younger population is a critical step in continuing to lessen the immense public health burden caused by the covid-19 pandemic."
Pfizer and its German partner BioNTech recently requested similar authorization in the European Union, with other countries to follow.
Children are far less likely than adults to get seriously ill from covid-19, yet they represent nearly 14% of the nation's coronavirus cases. At least 296 have died from covid-19 in the U.S. alone, and more than 15,000 have been hospitalized, according to a tally by the American Academy of Pediatrics.
That's not counting the toll of family members becoming ill or dying -- or the disruption to school, sports and other activities.
The American Academy of Pediatrics welcomed the FDA's decision.
"Our youngest generations have shouldered heavy burdens over the past year, and the vaccine is a hopeful sign that they will be able to begin to experience all the activities that are so important for their health and development," said American Academy of Pediatrics President Dr. Lee Savio Beers in a statement.
"Adolescents, especially, have suffered tremendously from the covid pandemic," said Kawsar Talaat, an assistant professor of international health at the Johns Hopkins Bloomberg School of Public Health. "Even though they're less likely than adults to be hospitalized or have severe illness, their lives really have been curtailed in many parts of the country. A vaccine gives them an extra layer of protection and allows them to go back to being kids."
The latest news is welcome for U.S. families struggling to decide what activities are safe to resume when the youngest family members remain unvaccinated.
"I can't feel totally comfortable because my boys aren't vaccinated," said Carrie Vittitoe, a substitute teacher and freelance writer in Louisville, Ky., who is fully vaccinated, as are her husband and 17-year-old daughter.
The FDA decision means her 13-year-old son soon could be eligible, leaving only her 11-year-old son unvaccinated. The family has not yet resumed going to church, and summer vacation will be a road trip so they do not have to get on a plane.
"We can't really go back to normal because two-fifths of our family don't have protection," Vittitoe said.
The decision that the two-shot regimen is safe and effective for younger adolescents had been anticipated by many parents and pediatricians, particularly with the growing gap between what vaccinated and unvaccinated people may do safely. Evidence suggests that schools can function at low risk with prevention measures, such as masks and social distancing. But vaccines are poised to increase confidence in resuming in-person activities and are regarded as pivotal to returning to normalcy.
Experts say children must get the shots if the country is to vaccinate the 70% to 85% of the population necessary to reach what's called herd immunity.
In the meantime, the Centers for Disease Control and Prevention says unvaccinated people -- including children -- should continue taking precautions such as wearing masks indoors and keeping their distance from other unvaccinated people outside of their households.
Robert Frenck, the researcher who led the adolescent trial at Cincinnati Children's Hospital Medical Center, said the study was designed to test whether it triggered immune responses, not whether it prevented disease. But because of the number of children who became ill in the placebo arm of the trial, it also became evident the vaccine offered robust protection.
"That really points out how much covid there is in the adolescent community," Frenck said.
The data has not been published or peer-reviewed, but Kathryn Edwards, a pediatric infectious-disease specialist at Vanderbilt University Medical Center, said the results announced by Pfizer were "pretty exciting -- it looked very effective and the immune responses were really good."
Edwards said she is comfortable that the benefits of vaccinations are clear among teens, noting that while children, in general, are at lower risk of severe covid-19 than adults, older adolescents seem to be more like adults in their risk for covid-19 than the very youngest children.
Cody Meissner, a pediatrician at Tufts Medical Center and a member of an external advisory committee to the FDA, said a pediatric vaccine is needed. But he said he would like to see more safety data because the messenger RNA technology at the core of vaccines from Pfizer-BioNTech and the biotechnology company Moderna does not have a long, established safety record, and its first large-scale use began in December.
Meissner abstained from the December vote that overwhelmingly recommended authorization of the Pfizer-BioNTech vaccine for people 16 and older because he thought the vaccine should be authorized in people 18 and older.
"For those who are eager to get it, it's important for them to understand that this is very rarely a severe disease in young adolescents, number one, and this is an entirely new vaccine," Meissner said. "I just don't want people to get too swept up in fear of hospitalization and death from covid-19 for the first few decades of life."
Pfizer is not the only company seeking to lower the age limit for its vaccine. Moderna recently said preliminary results from its study in 12- to 17-year-olds show strong protection and no serious side effects. Another U.S. company, Novavax, has a covid-19 vaccine in late-stage development and just began a study in 12- to 17-year-olds.
Next up is testing whether the vaccine works for even younger children. Both Pfizer and Moderna have begun U.S. studies in children ages 6 months to 11 years. Those studies explore whether babies, preschoolers and elementary-age kids will need different doses than teens and adults. Gruber said Pfizer expects its first results in the fall.
Outside of the U.S., AstraZeneca is studying its vaccine among 6- to 17-year-olds in Britain. And in China, Sinovac recently announced that it has submitted preliminary data to Chinese regulators showing its vaccine is safe in children as young as 3.
Trials in younger children are expected to take longer because researchers must step down gradually in age and determine a safe and effective dose. Gruber said data from tests in children as young as 2 years old may be available by September or October, with data on children as young as 6 months possible by the end of the year.
Within each age category, a separate risk-benefit assessment may take place. In the youngest children, given the low risk from the coronavirus, side effects may figure more prominently into the analysis. Researchers may end up choosing a lower dose of vaccine. The understanding of children's role in transmission may also evolve and help guide vaccine use and public policy.
"We are proceeding carefully, cautiously," Edwards said. "We're using the same rigid guidelines we use in all vaccines, and we take this very seriously. I think as time goes on and more information becomes available, some of the questions may be easier to address."
Information for this article was contributed by Carolyn Y. Johnson of The Washington Post and by Lauran Neergaard and Candice Choi of The Associated Press.