Pfizer
The CDC studied 464 patients between the ages of 12- to 18-years-old across 19 pediatric hospitals in the United States from June through September. The CDC noted that U.S. pediatric COVID-19 hospitalziation reached the highest level during the pandemic in early September due to the spread of the highly contagious Delta variant.
Of the total participant pool, 179 were patients who were infected with COVID-19, while 285 were part of the control group. While roughly 72% of the participants had at least one underlying condition--which increased their risk of severe infection--researchers found that 97% of those hospitalized with COVID were not vaccinated; only six COVID patients were vaccinated with the Pfizer-BioNTech vaccine, which is the only shot authorized for adolescents in the U.S.
The study also found that no vaccinated adolescents hospitalized with COVID were admitted into intensive care, compared to 43% of unvaccinated patients needing intensive care and 16% requiring life support during hospitalization, including ventilation; two of the critically ill patients (7%) died.
"This evaluation demonstrated that 2 doses of Pfizer-BioNTech vaccine were highly effective in preventing COVID-19 hospitalization among persons aged 12-18 years," CDC researchers wrote in the agency's Morbidity and Mortality Weekly Report published Tuesday. "Fings reinforce the importance of vaccination to protect U.S. youths against severe COVID-19."
The CDC's findings are comparable to the results of a study conducted in Israel, which found that the Pfizer-BioNTech vaccine was almost 92% effective in preventing hospitalization among adolescents. However, the Israeli study did not include enough cases to properly determine the vaccine's full efficacy against hospitalization, CDC researchers wrote.
Still, CDC researchers noted some limitations to the study, including its own small sample size, which prevented them from properly measuring the vaccines effectiveness in patients with underlying conditions. The CDC also said that it could not determine the vaccine's efficacy against different COVID variants and that patients could have misrepresented their self-reported vaccinated status.
So far, the U.S. Food and Drug Administration (FDA) has approved the Pfizer-BioNTech vaccine for any American aged 16 years or older. The vaccine also operated under emergency use for adolescents between the ages of 12- to 15-years-old, with the company waiting on full approval from the federal health regulator.
