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Study: Pfizer-BioNTech COVID-19 vaccine keeps youths out of hospital

October 19, 2021

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Two doses of Pfizer-BioNTech COVID-19 vaccine were highly effective in preventing hospitalization among adolescents ages 12-18 years, a new study from the Centers for Disease Control and Prevention (CDC) shows.

While a clinical trial showed the vaccine is 100% effective in preventing COVID-19 in youths ages 12-15 years, researchers wanted to look at how effective it is in preventing hospitalization in a real-world setting.

To do so, they conducted a case-control study of patients ages 12-18 admitted to 19 pediatric hospitals in 16 states from June through September. Their findings are published today in “Effectiveness of Pfizer-BioNTech mRNA Vaccination Against COVID-19 Hospitalization Among Persons Aged 12–18 Years — United States, June –September 2021” (Olson SM, et al. MMWR. Oct. 19, 2021).

Researchers compared the vaccination status of hospitalized patients with COVID-19 (cases) to patients without COVID-19 (controls).

Cases had COVID-19-like illness and tested positive for SARS-CoV-2 with a reverse transcription-polymerase chain reaction (RT-PCR) or antigen test. Controls either had COVID-19 symptoms but a negative RT-PCR or antigen test or had no COVID-19 symptoms and may not have been tested.

Among patients who had received Pfizer-BioNTech COVID-19 vaccine, only those who completed the two-dose series at least 14 days prior to illness onset were included.

The analysis included 464 patients (179 cases and 285 controls).

Results showed 3% of cases had been fully vaccinated compared to 33% of controls.

Among cases, 77 (43%) were admitted to the intensive care unit, 29 (16%) received life support and two died. All were unvaccinated.

Researchers also found that vaccination reduced the risk of COVID-related hospitalization by 93%.

“These data suggest that increasing vaccination coverage among this group could reduce the incidence of severe COVID-19 in the United States,” the authors concluded. “Further, as in-person school attendance increases, multicomponent preventive measures to reduce the incidence of severe COVID-19 among adolescents, including vaccination, are imperative.”

Nearly 6.2 million children have tested positive for COVID-19, according to data from the AAP and the Children’s Hospital Association. In the week ending Oct. 14, there were more than 131,000 new pediatric cases, and children made up about one-quarter of all new cases.

About 47% of 12- to 17-year-olds in the U.S. are fully vaccinated, according to an AAP report.

The Pfizer-BioNTech vaccine has been licensed by the Food and Drug Administration for those ages 16 years and older and has received an emergency use authorization (EUA) for those ages 12-15. EUA for children ages 5-11 could be granted in the next few weeks.


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