In:
Clinical Infectious Diseases, Oxford University Press (OUP), ( 2023-11-16)
Abstract:
During the 2022–2023 influenza season, the United States experienced the highest influenza-associated pediatric hospitalization rate since 2010–2011. Influenza A/H3N2 infections were predominant. Methods We analyzed acute respiratory illness (ARI)-associated emergency department or urgent care (ED/UC) encounters or hospitalizations at three health systems among children and adolescents aged 6 months–17 years who had influenza molecular testing during October 2022–March 2023. We estimated influenza A vaccine effectiveness (VE) using a test-negative approach. The odds of vaccination among influenza-A-positive cases and influenza-negative controls were compared after adjusting for confounders and applying inverse-propensity-to-be-vaccinated weights. We developed overall and age-stratified VE models. Results Overall, 13,547 of 44,787 (30.2%) eligible ED/UC encounters and 263 of 1,862 (14.1%) hospitalizations were influenza-A-positive cases. Among ED/UC patients, 15.2% of influenza-positive versus 27.1% of influenza-negative patients were vaccinated; VE was 48% (95% confidence interval [CI], 44%–52%) overall, 53% (95% CI, 47%–58%) among children aged 6 months–4 years and 38% (95% CI, 30%–45%) among those aged 9–17 years. Among hospitalizations, 17.5% of influenza-positive versus 33.4% of influenza-negative patients were vaccinated; VE was 40% (95% CI, 6%–61%) overall, 56% (95% CI, 23%–75%) among children ages 6 months–4 years and 46% (95% CI, 2%–70%) among those 5–17 years. Conclusions During the 2022–2023 influenza season, vaccination reduced the risk of influenza-associated ED/UC encounters and hospitalizations by almost half (overall VE 40–48%). Influenza vaccination is a critical tool to prevent moderate-to-severe influenza illness in children and adolescents.
Type of Medium:
Online Resource
ISSN:
1058-4838
,
1537-6591
Language:
English
Publisher:
Oxford University Press (OUP)
Publication Date:
2023
detail.hit.zdb_id:
2002229-3
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