Effectiveness of Pfizer-BioNTech mRNA Vaccination Against COVID-19 Hospitalization Among Persons Aged 12-18 Years - United States, June-September 2021.

Olson, Samantha M; Newhams, Margaret M; Halasa, Natasha B; Price, Ashley M; Boom, Julie A; Sahni, Leila C; Irby, Katherine; Walker, Tracie C; Schwartz, Stephanie P; Pannaraj, Pia S; Maddux, Aline B; Bradford, Tamara T; Nofziger, Ryan A; Boutselis, Benjamin J; Cullimore, Melissa L; Mack, Elizabeth H; Schuster, Jennifer E; Gertz, Shira J; Cvijanovich, Natalie Z; Kong, Michele; Cameron, Melissa A; Staat, Mary A; Levy, Emily R; Chatani, Brandon M; Chiotos, Kathleen; Zambrano, Laura D; Campbell, Angela P; Patel, Manish M; Randolph, Adrienne G

Pfizer-BioNTech COVID-19 vaccine is authorized for use in children and adolescents aged 12-15 years and is licensed by the Food and Drug Administration (FDA) for persons aged ≥16 (1). A randomized placebo-controlled trial demonstrated an efficacy of 100% (95% confidence interval [CI] = 75.3%-100%) in preventing outpatient COVID-19 in persons aged 12-15 years (2); however, data among adolescents on vaccine effectiveness (VE) against COVID-19 in real-world settings are limited, especially among hospitalized patients. In early September 2021, U.S. pediatric COVID-19 hospitalizations reached the highest level during the pandemic (3,4). In a test-negative, case-control study at 19 pediatric hospitals in 16 states during June 1-September 30, 2021, the effectiveness of 2 doses of Pfizer-BioNTech vaccine against COVID-19 hospitalization was assessed among children and adolescents aged 12-18 years. Among 464 hospitalized persons aged 12-18 years (179 case-patients and 285 controls), the median age was 15 years, 72% had at least one underlying condition, including obesity, and 68% attended in-person school. Effectiveness of 2 doses of Pfizer-BioNTech vaccine against COVID-19 hospitalization was 93% (95% CI = 83%-97%), during the period when B.1.617.2 (Delta) was the predominant variant. This evaluation demonstrated that 2 doses of Pfizer-BioNTech vaccine are highly effective at preventing COVID-19 hospitalization among persons aged 12-18 years and reinforces the importance of vaccination to protect U.S. youths against severe COVID-19.