An expert panel unanimously recommended Pfizer-BioNTech's Covid vaccine for five- to 11-year-olds on Tuesday, the penultimate step in the process that will allow injections in young children to begin this week in the United States.
The Centers for Disease Control and Prevention (CDC), the top US public health agency, was expected to endorse that recommendation later Tuesday.
The Food and Drug Administration (FDA) approved the vaccine for the age group last week, but since it is distributed through public services, the CDC is also required to recommend it.
The government was well ahead of the decision, procuring enough doses for the 28 million US children in the age group and beginning to ship them across the country.
Since the FDA approval, "there hasn't been a moment that teams have not been picking, packing and shipping vaccines," Jeff Zients, the White House pandemic coordinator, said Monday.
"We are planning on some vaccinations towards the end of this week," he said, adding that the program will be "really hitting full strength the week of November 8."
The CDC convened a panel of independent scientists on Tuesday to review the available data on the status of the outbreak in children, the effectiveness of Pfizer's vaccine, and its possible side effects during a day of live-streamed discussions.
The main concern was the risk of myocarditis, an inflammation of the heart muscle, detected in adolescents and young adults (mostly males) after vaccination with the Pfizer or Moderna shots.
Health authorities have confirmed nearly 880 cases in people under 30 years of age, of which approximately 830 required hospitalization.
Nine deaths are suspected to have been related to myocarditis after the vaccine.
But of six cases so far reviewed, vaccine-related myocarditis was ultimately not identified "as the cause of death," pediatric cardiologist Dr. Matthew Oster said in a presentation.
"I'm much more worried about what would happen to their child if they get Covid, for patients who don't have heart disease, than I am if they were to get this vaccine," he added.
There have been more than 1.9 million cases of Covid-19 among five- to 11-year-olds in the United States, and more than 8,300 hospitalizations, more than 2,300 cases of MIS-C (pediatric multisystem inflammatory syndrome), and about 100 deaths.
The expected benefits of vaccinating children also include fewer school closures, and a possible reduction in transmission of the epidemic into the general population.
"If I had a grandchild, I would certainly get that grandchild vaccinated as soon as possible," said Beth Bell, an infectious disease specialist and committee member.
"We have excellent evidence of efficacy and safety. We have a favourable risk benefit analysis."