Title
Vaccine Effectiveness Against Pediatric Influenza Hospitalizations and Emergency Visits.
Document Type
Article
Publication Date
11-2020
Identifier
DOI: 10.1542/peds.2020-1368
Abstract
BACKGROUND: Influenza A(H1N1)pdm09 viruses initially predominated during the US 2018-2019 season, with antigenically drifted influenza A(H3N2) viruses peaking later. We estimated vaccine effectiveness (VE) against laboratory-confirmed influenza-associated hospitalizations and emergency department (ED) visits among children in the New Vaccine Surveillance Network.
METHODS: We tested children 6 months to 17 years with acute respiratory illness for influenza using molecular assays at 7 pediatric hospitals (ED patientssites). Vaccination status sources were parental report, state immunization information systems and/or provider records for inpatients, and parental report alone for ED patients. We estimated VE using a test-negative design, comparing odds of vaccination among children testing positive versus negative for influenza using multivariable logistic regression.
RESULTS: Of 1792 inpatients, 226 (13%) were influenza-positive: 47% for influenza A(H3N2), 36% for A(H1N1)pdm09, 9% for A (not subtyped), and 7% for B viruses. Among 1944 ED children, 420 (22%) were influenza-positive: 48% for A(H3N2), 35% for A(H1N1)pdm09, 11% for A (not subtyped), and 5% for B viruses. VE was 41% (95% confidence interval [CI], 20% to 56%) against any influenza-related hospitalizations, 41% (95% CI, 11% to 61%) for A(H3N2), and 47% (95% CI, 16% to 67%) for A(H1N1)pdm09. VE was 51% (95% CI, 38% to 62%) against any influenza-related ED visits, 39% (95% CI, 15% to 56%) against A(H3N2), and 61% (95% CI, 44% to 73%) against A(H1N1)pdm09.
CONCLUSIONS: The 2018-2019 influenza vaccine reduced pediatric influenza A-associated hospitalizations and ED visits by 40% to 60%, despite circulation of a drifted A(H3N2) clade.
Journal Title
Pediatrics
Volume
146
Issue
5
Recommended Citation
Campbell, A. P., Ogokeh, C., Lively, J. Y., Staat, M. A., Selvarangan, R., Halasa, N. B., Englund, J. A., Boom, J. A., Weinberg, G. A., Williams, J. V., McNeal, M., Harrison, C. J., Stewart, L. S., Klein, E. J., Sahni, L. C., Szilagyi, P. G., Michaels, M. G., Hickey, R. W., Moffatt, M., Pahud, B. A., Schuster, J. E., Weddle, G., Rha, B., Fry, A. M., Patel, M. Vaccine Effectiveness Against Pediatric Influenza Hospitalizations and Emergency Visits. Pediatrics 146, (2020).
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