The Centers for Disease Control and Prevention is recommending that all children ages 5 through 11 get a low-dose COVID-19 vaccine made by Pfizer-BioNTech.

The move clears the way for shots to be administered as soon as tomorrow, though it may be a few days before the vaccine is widely available.

CDC director Rochelle Walensky issued the recommendation Tuesday, just hours after a unanimous vote by the CDC's Advisory Committee on Immunization Practices supporting the use of the vaccine for children in this age group.

Walensky's decision means that approximately 28 million children ages 5 through 11 will be eligible for the shots.

President Biden issued a statement calling the decision "a turning point in our battle against COVID-19," and said the federal government has purchased enough of the low-dose children's vaccine "for every child in America."

Shipments of the vaccine started last Friday following the Food and Drug Administration's decision to authorize the vaccine in this age group. White House COVID-19 response coordinator Jeffrey Zients said some 15 million doses are being shipped this week, and the federal program for distributing the vaccine "will be fully operational" by next Monday, Nov. 8.

Some school districts have already scheduled vaccination drives in coming weeks, before the Thanksgiving holiday, though some districts have said they will not be providing the vaccines through schools.

The Pfizer-BioNTech pediatric vaccine is one-third the adult dose and, like the adult formulation, is given in two doses, three weeks apart. The lower dose was chosen to minimize side effects and still produce strong immunity, Pfizer says.

Before the advisory committee meeting Tuesday, Walensky called this "a monumental day" as she urged the panel to consider the toll that COVID-19 has had on children. The CDC's latest data show that 172 children ages 5 to 11 have died from COVID-19 and more than 8,300 have been hospitalized.

"We also know that beyond the clinical impact of COVID on children, there have been detrimental social and mental health impacts that we are just beginning to fully understand," Walensky said in giving her charge to the panel. "It is our ongoing responsibility to make sure as many people as possible are vaccinated and protected from COVID-19."

Her statements left little doubt that she supported a broad recommendation to vaccinate all children 5 to 11 years old.

The vaccine is being shipped to pediatricians' and family doctors' offices, Zients said, as well as to community health centers, pharmacies, tribal health centers and other providers. School-based vaccine administration sites will also be included in some areas.

Parents will not need a doctor's order to get a vaccine, Zients said, though parents with questions may want to discuss the vaccine with a trusted health provider.

In a statement announcing her decision, Walensky underlined that point. "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," she said.

During the Tuesday meeting of the CDC's Advisory Committee on Immunization Practices, panel members reviewed and discussed the science behind the FDA's Friday authorization of the vaccine in all children 5 to 11 years old. That authorization was based mostly on a Pfizer-BioNTech study of 4,600 children worldwide, of whom approximately 3,100 got the low-dose vaccine and about 1,500 got a placebo.

These studies showed that the vaccine is about 91% effective against symptomatic COVID-19. The immune system response to the vaccine, as measured by antibodies, was comparable to the response seen in 16- to 25-year-olds.

The advisers spent considerable time weighing the public health need of a children's vaccine for a disease that is not as often severe or deadly as it is in adults. In the end, the prevalence of COVID-19 across the U.S. and the number of severe cases and deaths led them to recommend universal use of the vaccine in the 5-11 age group.

The most recent CDC data from September 2021 show that 38% of children in the 5-11 age group have antibodies to the virus that causes COVID-19, indicating that they've been infected. Dr. Jefferson Jones, a medical officer with the CDC, said that young children are at least as likely to be infected as adults. More than 1.9 million cases have been reported in 5- to 11-year-olds.

Overall, there have been more than 8,300 children ages 5 to 11 hospitalized with COVID-19. More than 2,300 children in this age group have gotten a related illness called MIS-C, a severe condition that affects multiple organs and can be fatal. The 5-11 age group had the highest number of cases of MIS-C among children.

Hospitalization rates and severity of hospitalized cases for COVID-19 in this age group have been similar to what has been seen in past years for influenza, according to Jones.

Hospitalization rates for COVID-19 are three times higher for non-Hispanic Black, non-Hispanic American Indian/Alaska Native, and Hispanic children compared with non-Hispanic white children, Jones said.

One relatively rare side effect that generated considerable discussion at Tuesday's meeting is myocarditis, a form of heart inflammation. It also occurs as a complication of several viral infections, including COVID-19, and is most often seen in adolescent boys and young men. It typically clears up within weeks or a few months.

The CDC has confirmed 877 cases of myocarditis after the Pfizer or Moderna vaccine in people age 30 or younger, but there have been no deaths, said Dr. Matthew Oster, who studies myocarditis for the CDC and is a pediatric cardiologist at Children's Healthcare of Atlanta. He explained that COVID-19 itself can cause myocarditis and other heart-related issues, including MIS-C, which often affects the heart.

"The bottom line is getting COVID, I think, is much riskier to the heart than getting this vaccine," Oster said.

As regards safety, some who testified during a public comment period, as well as other commentators, have questioned whether the study used by the FDA to grant emergency use authorization is large enough to assure parents that the vaccine is safe in young children.

In response, Dr. Doran Fink, clinical deputy director of the FDA's Division of Vaccines and Related Products Applications, told the meeting that the safety database size for this age group is "at the upper end — or even beyond — of the safety database size that it has supported licensure of other preventive vaccines for infectious diseases."

Vaccinations of 5- to 11-year-olds starting this month could potentially prevent 600,000 cases of COVID-19 by March of next year, according to CDC models, said Dr. Sara Oliver of the CDC. Vaccination of 5- to 11-year-olds "would dampen, but not eliminate," the possibility that a new variant might emerge, she said.

Acknowledging that some parents are hesitant to have their children vaccinated right away, Dr. Matthew Daley, a member of the advisory committee, said, "We hear you loud and clear."

"Of course you only want what's best for your child," he said. "I encourage you to talk to your family physician or pediatrician, [so] they can walk through this with you."

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