Effectiveness of BNT162b2 (Pfizer-BioNTech) mRNA Vaccination Against Multisystem Inflammatory Syndrome in Children Among Persons Aged 12–18 Years — United States, July–December 2021
Authors: Laura D. Zambrano, Margaret M. Newhams, Samantha M. Olson, Natasha B. Halasa, Ashley M. Price, Julie A. Boom, Leila C. Sahni, Satoshi Kamidani, Keiko M. Tarquinio, Aline B. Maddux, Sabrina M. Heidemann, Samina S. Bhumbra, Katherine E. Bline, Ryan A. Nofziger, Charlotte V. Hobbs, Tamara T. Bradford, Natalie Z. Cvijanovich, Katherine Irby, Elizabeth H. Mack, Melissa L. Cullimore, Pia S. Pannaraj, Michele Kong, Tracie C. Walker, Shira J. Gertz, Kelly N. Michelson, Melissa A. Cameron, Kathleen Chiotos, Mia Maamari, Jennifer E. Schuster, Amber O. Orzel, Manish M. Patel, Angela P. Campbell, Adrienne G. Randolph, Meghan Murdock, Mary Glas Gaspers, Katri V. Typpo, Connor P. Kelley, Ronald C. Sanders, Masson Yates, Chelsea Smith, Katheryn Crane, Geraldina Lionetti, Juliana Murcia-Montoya, Matt S. Zinter, Denise Villarreal-Chico, Adam L. Skura, Harvey Peralta, Justin M. Lockwood, Emily Port, Imogene A. Carson, Brandon M. Chatani, Laila Hussaini, Nadine Baida, Bria M. Coates, Courtney M. Rowan, Mary Stumpf, Marla S. Johnston, Benjamin J. Boutselis, Suden Kucukak, Sabrina R. Chen, Edie Weller, Laura Berbert, Jie He, Heidi R. Flori, Janet R. Hume, Ellen R. Bruno, Lexie A. Goertzen, Emily R. Levy, Supriya Behl, Noelle M. Drapeau, Lora Martin, Lacy Malloch, Cameron Sanders, Kayla Patterson, Anita Dhanrajani, Shannon M. Hill, Abigail Kietzman, Valerie H. Rinehart, Lauren A. Hoody, Stephanie P. Schwartz, Angelo G. Navas, Paris C. Bennett, Nicole A. Twinem, Merry L. Tomcany, Mary Allen Staat, Chelsea C. Rohlfs, Amber Wolfe, Rebecca L. Douglas, Kathlyn Phengchomphet, Megan M. Bickford, Lauren E. Wakefield, Laura Smallcomb, Laura S. Stewart, Meena Golchha, Jennifer N. Oates, Cindy Bowens
Journal: MMWR Morbidity and Mortality Weekly Report (2022)

Multisystem inflammatory syndrome in children (MIS-C) is a severe postinfectious hyperinflammatory condition, which generally occurs 2-6 weeks after a typically mild or asymptomatic infection with SARS-CoV-2, the virus that causes COVID-19 (1-3). In the United States, the BNT162b2 (Pfizer-BioNTech) COVID-19 vaccine is currently authorized for use in children and adolescents aged 5-15 years under an Emergency Use Authorization and is fully licensed by the Food and Drug Administration for persons aged ≥16 years (4). Prelicensure randomized trials in persons aged ≥5 years documented high vaccine efficacy and immunogenicity (5),§ and real-world studies in persons aged 12-18 years demonstrated high vaccine effectiveness (VE) against severe COVID-19 (6). Recent evidence suggests that COVID-19 vaccination is associated with lower MIS-C incidence among adolescents (7); however, VE of the 2-dose Pfizer-BioNTech regimen against MIS-C has not been evaluated. The effectiveness of 2 doses of Pfizer-BioNTech vaccine received ≥28 days before hospital admission in preventing MIS-C was assessed using a test-negative case-control design¶ among hospitalized patients aged 12-18 years at 24 pediatric hospitals in 20 states** during July 1-December 9, 2021, the period when most MIS-C patients could be temporally linked to SARS-CoV-2 B.1.617.2 (Delta) variant predominance. Patients with MIS-C (case-patients) and two groups of hospitalized controls matched to case-patients were evaluated: test-negative controls had at least one COVID-19-like symptom and negative SARS-CoV-2 reverse transcription-polymerase chain reaction (RT-PCR) or antigen-based assay results, and syndrome-negative controls were hospitalized patients without COVID-19-like illness. Among 102 MIS-C case-patients and 181 hospitalized controls, estimated effectiveness of 2 doses of Pfizer-BioNTech vaccine against MIS-C was 91% (95% CI = 78%-97%). All 38 MIS-C patients requiring life support were unvaccinated. Receipt of 2 doses of the Pfizer-BioNTech vaccine is associated with a high level of protection against MIS-C in persons aged 12-18 years, highlighting the importance of vaccination among all eligible children.