Vaccine Effectiveness Against Influenza Hospitalization and Emergency Department Visits in 2 A(H3N2) Dominant Influenza Seasons Among Children <18 Years Old-New Vaccine Surveillance Network 2016-2017 and 2017-2018.
Studies have shown egg-adaptive mutations in influenza vaccine strains that might have impaired protection against circulating A(H3N2) influenza viruses during the 2016-2017 and 2017-2018 seasons. We used the test-negative design and multivariable models to assess vaccine effectiveness against influenza-associated hospitalization and emergency department visits among children (old) during the 2016-2017 and 2017-2018 seasons. Effectiveness was 71% (95% confidence interval, 59%-79%), 46% (35%-55%), and 45% (33%-55%) against A(H1N1)pdm09, A(H3N2), and B viruses respectively, across both seasons. During high-severity seasons with concerns for vaccine mismatch, vaccination offered substantial protection against severe influenza outcomes requiring hospitalization or emergency department visits among children.
The Journal of infectious diseases
Adolescent; Case-Control Studies; Child; Emergency Service, Hospital; Hospitalization; Humans; Influenza A Virus, H1N1 Subtype; Influenza A Virus, H3N2 Subtype; Influenza B virus; Influenza Vaccines; Influenza, Human; Seasons; Vaccination; Vaccine Efficacy
Influenza; children; test negative design; vaccination
Kim SS, Naioti EA, Halasa NB, et al. Vaccine Effectiveness Against Influenza Hospitalization and Emergency Department Visits in 2 A(H3N2) Dominant Influenza Seasons Among Children <18 Years Old-New Vaccine Surveillance Network 2016-2017 and 2017-2018. J Infect Dis. 2022;226(1):91-96. doi:10.1093/infdis/jiab624