Two doses of the BNT162b2 (Pfizer-BioNTech) vaccine were 93% effective against adolescent hospitalization for COVID-19, a case-control study at 19 pediatric hospitals in 16 states showed.
The study provides real-world evidence that the vaccine was highly protective against hospitalization among adolescents even as the Delta variant (B.1.617.2) became the predominant strain. The highly transmissible SARS-CoV-2 variant contributed to a surge in pediatric hospitalizations over the summer and into the early fall. Previously, a clinical trial showed the vaccine was 100% effective against symptomatic COVID-19 among individuals aged 12 to 15 years.
The new study involved 179 individuals aged 12 to 18 years hospitalized for laboratory-confirmed COVID-19 and a control group of 285 adolescents hospitalized for other causes between June and September 2021. It excluded partially vaccinated individuals.
Vaccination coverage was 3% in the COVID-19 group and 33% in the control group. Six vaccinated patients were hospitalized for COVID-19, and none were admitted to the intensive care unit (ICU) or died. In contrast, 173 unvaccinated patients were hospitalized for COVID-19, 77 were admitted to ICUs, and 29 required life support, including 2 who died. Unvaccinated patients with COVID-19 stayed a median of 5 days in the hospital, 2 days longer than their vaccinated peers with the illness.
Only 46% of US children and adolescents aged 12 to 15 years and 54% aged 16 to 17 years were vaccinated when the study was published. Boosting these rates could help prevent severe COVID-19 in the US, the authors wrote.
“[A]s in-person school attendance increases, multicomponent preventive measures to reduce the incidence of severe COVID-19 among adolescents, including vaccination, are imperative,” the authors wrote.