The United States can now start giving children aged 5-11 the Pfizer-BioNtech Covid vaccine, US health authorities said Tuesday in a move hailed by President Joe Biden as a "turning point" in the fight against the pandemic.

Days after gaining authorization from the Food and Drug Administration, the vaccine was endorsed by the Centers for Disease Control and Prevention, clearing the way for the vaccination of up to 28 million children.

The government was well ahead of the decision, procuring enough doses for the children in the 5-11 age group and beginning to ship them across the country.

"Today, we have reached a turning point in our battle against Covid-19," Biden said in a statement released by the White House.

Vaccinating younger children will "allow parents to end months of anxious worrying about their kids, and reduce the extent to which children spread the virus to others. It is a major step forward for our nation in our fight to defeat the virus," the president continued.

The government has already secured enough vaccine for every child in America, he said, adding that over the weekend officials began the process of packing and shipping millions of doses.

"The program will ramp up over the coming days, and (be) fully up and running during the week of November 8," he said.

The vaccine will still be given in two injections, three weeks apart. The dosage has been adjusted to 10 micrograms per injection, compared to 30 micrograms for the older age groups.

The caps on the children's vials will be orange, making them easily recognizable compared to the purple caps on the vials for older groups.

"As a mom, I encourage parents with questions to talk to their pediatrician, school nurse or local pharmacist to learn more about the vaccine and the importance of getting their children vaccinated," CDC director Rochelle Walensky said in a statement.

Some parents were not waiting, however.

At the Hartford Hospital in Hartford, Connecticut late Tuesday a group of six children were among the first in the country to receive the vaccine.

"I could cry," one mother, Liz Cronin, told AFP. "We've all been waiting for it for so long for our kids to ... have this almost sense of normalcy back."

Six-year-old Kareem Omar said the shot "doesn't really hurt," adding: "Do it for the sake of America. Because it's helping America and the world, so, life is better for each and every person on Earth."

'More worried' about Covid

The CDC had 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 panel unanimously recommended the vaccine, and the CDC then endorsed that recommendation.

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.

According to a survey of 1,000 parents presented Tuesday by the CDC, 57 percent said they would "definitely" or "probably" get their child vaccinated.

"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 favorable risk benefit analysis."