(CNN) US Centers for Disease Control and Prevention Director Dr. Rochelle Walensky said Wednesday the agency now recommends the use of Pfizer/BioNTech's coronavirus vaccine in 12-15-year-olds.
"Today, I adopted CDC's Advisory Committee on Immunization Practices' (ACIP) recommendation that endorsed the safety and effectiveness of the Pfizer-BioNTech COVID-19 vaccine and its use in 12- through 15-year-old adolescents," Walensky said in a statement.
ACIP voted unanimously Wednesday to recommend giving Pfizer/BioNTech's Covid-19 vaccine to kids as young as 12.
"CDC now recommends that this vaccine be used among this population, and providers may begin vaccinating them right away," Walensky said.
The US Food and Drug Administration extended its emergency use authorization for the vaccine in 12-15-year-olds Monday.
President Joe Biden welcomed the decision, noting that 17 million more Americans would now be eligible for vaccination.
"Now, I encourage each of them and their parents to get their vaccination shots right away," Biden said.
"This is one more step to gaining immunity and bringing the pandemic closer to an end," said Dr. José Romero, who chairs ACIP and who is also the Secretary of the Arkansas Department of Health.
"We still need to vaccinate the rest of the world, but we have made significant steps and are on the road."
CVS said its pharmacies will begin to administer Pfizer's Covid-19 vaccine to children ages 12-15 on Thursday.
Consent from a parent or guardian will be required to get the vaccine in a CVS pharmacy, and an adult must be present with the child to get the vaccine.
Dr. Sara Oliver of the CDC's National Center for Immunization and Respiratory Diseases had briefed the committee on the risks and benefits of the vaccine.
"Adolescents 12-17 years of age are at risk of severe illness from Covid-19," Oliver said.
"There have been over 1.5 million reported cases and over 13,000 hospitalizations to date among adolescents 12 to 17 years," she added.
A comparison of hospitalization rates from past annual influenza epidemics shows more children and teens have been hospitalized because of Covid-19 than for flu, Oliver said.
"Overall the hospitalization rate for Covid in this population is higher than the influenza-associated hospitalization rate for the same age group during the 2009 H1N1 pandemic," she said. The Covid hospitalization rate for 12-17-year-olds has also been significantly higher for Covid than it was for flu in 2017, 2018, 2019 and 2020, she said.
Plus, it's become clear that teens and children are a source of spread of the virus, she said.
"Adults living in a household with a child engaged in full-time in-person school had an increase in odds of reporting Covid-19 like illness, loss of taste/smell, or positive SARS-CoV-2 test within previous 14 days."
Early in the pandemic, older adults accounted for more cases, Oliver said. Now, as more adults are vaccinated, children and teens are making up a larger share of infections.
"In April, 9% of cases were aged 12-17 years, which actually represents a larger proportion of cases than adults 65 and older," she told the ACIP meeting.
"However, we note that diagnosed and reported cases are an underestimate," she added. Adjusted estimates, she said, showed 22 million children ages 5-17 had been infected with coronavirus, accounting for 19% of all infections. The CDC has said the official count of diagnosed coronavirus cases underestimates the true count.
In the 12-17 age group, 127 have died from Covid-19.
Oliver also noted that 3,742 cases of multisystem inflammatory syndrome in children, or MIS-C, have been reported. It's a rare but serious complication of coronavirus infection that affects multiple organs. It affects minorities disproportionately; 63% of reported cases have been among Black and Latino children. It kills 1%-2% of patients.
The vaccine has been shown to be safe and effective in clinical trials, Oliver noted. "The clinical trial for the Pfizer-BioNTech Covid-19 vaccine demonstrated efficacy against symptomatic, laboratory-confirmed Covid-19. The efficacy was 100%," she said.
Adverse events were very rare and no serious adverse events were linked to the vaccine. None of the 2,200 12-15-year-olds in the clinical trial suffered a severe allergic reaction known as anaphylaxis.
It's also feasible to vaccinate younger teens and children, Oliver said."Increasing access to primary care providers serving adolescents has the benefits of utilizing trusted providers for providing information and education about Covid vaccines, as well as vaccinating against Covid," Oliver told ACIP.
Sites provided by the federal Health Resources and Services Administration (HRSA), an agency that provides health services to uninsured and otherwise vulnerable groups and that is helping vaccination efforts, are another resource for kids, Oliver said.
"Pharmacies and HRSA sites have a wide footprint across the nation, and can rapidly expand to provide Covid vaccines for adolescent school-based vaccinations, have the benefit of reaching adolescents in their own communities, as well as being trusted sources of information for communities," Oliver said.
Federally qualified health centers are another potential place to vaccinate children and teens, she said.
While most states will wait for the CDC go-ahead, some states allowed the vaccination of the younger adolescents starting Tuesday -- among them, Georgia and some districts of North Carolina.
The CDC also gave guidance that should make it easier to vaccinate children and teens.
Doctors and other clinicians had been advised to avoid giving coronavirus vaccine within two weeks of any other vaccine. But Dr. Kate Woodworth of the CDC's birth defects division said that advice has now changed.
"Due to the novelty of the Covid-19 vaccines, the previous recommendation was to administer Covid-19 vaccines alone, with a minimum interval of 14 days before or after administration of any other vaccine, to better understand any adverse events," Woodworth told ACIP.
"Extensive experience with non-Covid-19 vaccines has demonstrated that immunogenicity and adverse event profiles are generally similar when vaccines are administered simultaneously as when they are administered alone," she added.
Later, the CDC added that it was not yet known whether people might be more likely to have a reaction if multiple vaccines were given together with a Covid vaccine.
"For these reasons, the clinical considerations regarding co-administration are being updated to state that Covid-19 and other vaccines may now be administered without regard to timing. This includes simultaneous administration of Covid-19 with other vaccines on the same day, as well as coadministration within 14 days."
Woodworth noted that the number of childhood vaccinations has fallen off and many US kids need to catch up on their routine vaccines, including vaccinations against influenza, tetanus, meningitis and human papillomavirus (HPV).
The American Academy of Pediatrics also endorsed the practice of giving vaccines together and urged parents to vaccinate their children against Covid-19 as soon as possible.
Pfizer said last week it expects to submit for emergency use authorization for its Covid-19 vaccine for children ages 2 to 11 in September. Its vaccine safety and efficacy study in children ages 6 months to 11 years old is ongoing.
The FDA also scheduled a meeting of its Vaccines and Related Biological Products Advisory Committee for June 10 to discuss the potential extension of EUA to children under 12.