Since the start of the pandemic, very few adolescents have become ill enough with Covid-19 to be hospitalized. But of those who did, about one-third were admitted to intensive care units, and 5 percent required ventilators, the Centers for Disease Control and Prevention reported on Friday.
These findings underscore the importance of vaccinating children against the coronavirus, experts said. “Much of this suffering can be prevented,” Dr. Rochelle P. Walensky, the C.D.C. director, said in a statement. “Vaccination is our way out of this pandemic.”
The data also run counter to claims that influenza is more threatening to children than Covid-19, an argument that has been used to reopen schools and to question the value of coronavirus vaccines for children.
The number of hospitalizations related to Covid-19 among adolescents in the United States was about three times as high as hospitalizations linked to influenza over three recent flu seasons, the study found.
“There’s a very strong case to be made for preventing a disease that causes hospitalizations and deaths, not to mention contributing to community transmission,” said Dr. Yvonne Maldonado, chair of the committee on infectious diseases at the American Academy of Pediatrics.
Children have a much lower likelihood overall of becoming severely ill or dying from Covid-19, compared with adults, but the risks are thought to increase with age. According to the most recent data collected by the academy, nearly four million children have tested positive for the coronavirus since the pandemic began, compared with about 30 million cases among adults.
Still, about 16,500 children have been hospitalized for Covid-19 since the pandemic began, and at least 322 have died, making it one of the leading causes of death among children, Dr. Maldonado noted.
“It sounds like it’s not a lot of deaths,” especially compared with 600,000 dead in the United States, she said. But “it should still be horrifying that 300 to 600 kids are dying because of something that is preventable.”
The new C.D.C. report focused on hospitalizations from Covid-19 among children ages 12 to 17. The rate of hospitalizations in that group was a small fraction of that among adults, but still higher than the rate seen in children ages 5 to 11, the report found.
The researchers also tallied Covid-19 hospitalizations among children ages 12 to 17 from March 1, 2020, to April 24, 2021. The data came from Covid-Net, a population-based surveillance system in 14 states, covering about 10 percent of Americans.
The number of adolescents hospitalized with Covid-19 declined in January and February of this year, but rose again in March and April. From Jan. 1, 2021, to March 31, 204 adolescents were likely hospitalized primarily for Covid-19. Most of the children had at least one underlying medical condition, such as obesity, asthma or a neurological disorder.
The rate may have increased this spring because of the more contagious variants of the coronavirus in circulation, as well as school reopenings that brought children together indoors, and looser adherence to precautions like wearing masks and social distancing, the researchers said.
None of the children died, but about one-third were admitted to the intensive care unit, and 5 percent required invasive mechanical ventilation. Roughly two-thirds of the hospitalized adolescents were Black or Hispanic, reflecting the greater risk posed by the virus to these populations.
The researchers compared the numbers for Covid-19 with hospitalizations for flu in the same age group during the 2017-18, 2018-19 and 2019-20 flu seasons. From Oct. 1, 2020, to April 24, 2021, hospitalization rates for Covid-19 among adolescents were 2.5 to 3 times the rate for seasonal flu in previous years.
The data lend urgency to the drive to get more teenagers vaccinated, said Dr. Walensky, who added that she was “deeply concerned” by the numbers.
The Food and Drug Administration approved the Pfizer-BioNTech coronavirus vaccine for children ages 12 to 15 on May 12. The vaccine was approved for anyone older in December.
Of the 24 million children ages 12 to 17 in the United States, about 6.4 million have received at least one dose of the vaccine, and only 2.3 million are fully vaccinated.