Tang, JuanjieNovak, TanyaHecker, JulianGrubbs, GabrielleTuz Zahra, FatemaBellusci, LorenzaPourhashemi, SaraChou, JanetMoffitt, KristinHalasa, Natasha B.Schwartz, Stephanie P.Walker, Tracie C.Tarquinio, Keiko M.Zinter, Matt S.Staat, Mary A.Gertz, Shira J.Cvijanovich, Natalie Z.Schuster, Jennifer E.Loftis, Laura L.Coates, Bria M.Mack, Elizabeth H.Irby, KatherineFitzgerald, Julie C.Rowan, Courtney M.Kong, MicheleFlori, Heidi R.Maddux, Aline B.Shein, Steven L.Crandall, HillaryHume, Janet R.Hobbs, Charlotte V.Tremoulet, Adriana H.Shimizu, ChisatoBurns, Jane C.Chen, Sabrina R.Moon, Hye KyungLange, ChristophRandolph, Adrienne G.Khurana, Surender2023-06-162023-06-162022-05-27Tang J, Novak T, Hecker J, et al. Cross-reactive immunity against the SARS-CoV-2 Omicron variant is low in pediatric patients with prior COVID-19 or MIS-C [published correction appears in Nat Commun. 2022 Aug 12;13(1):4732]. Nat Commun. 2022;13(1):2979. Published 2022 May 27. doi:10.1038/s41467-022-30649-1https://hdl.handle.net/1805/33808Neutralization capacity of antibodies against Omicron after a prior SARS-CoV-2 infection in children and adolescents is not well studied. Therefore, we evaluated virus-neutralizing capacity against SARS-CoV-2 Alpha, Beta, Gamma, Delta and Omicron variants by age-stratified analyses (<5, 5-11, 12-21 years) in 177 pediatric patients hospitalized with severe acute COVID-19, acute MIS-C, and in convalescent samples of outpatients with mild COVID-19 during 2020 and early 2021. Across all patients, less than 10% show neutralizing antibody titers against Omicron. Children <5 years of age hospitalized with severe acute COVID-19 have lower neutralizing antibodies to SARS-CoV-2 variants compared with patients >5 years of age. As expected, convalescent pediatric COVID-19 and MIS-C cohorts demonstrate higher neutralization titers than hospitalized acute COVID-19 patients. Overall, children and adolescents show some loss of cross-neutralization against all variants, with the most pronounced loss against Omicron. In contrast to SARS-CoV-2 infection, children vaccinated twice demonstrated higher titers against Alpha, Beta, Gamma, Delta and Omicron. These findings can influence transmission, re-infection and the clinical disease outcome from emerging SARS-CoV-2 variants and supports the need for vaccination in children.en-USAttribution 4.0 InternationalViral infectionSARS-CoV-2AntibodiesVaccinesArticle