A Retrospective Test-Negative Case-Control Study to Evaluate Influenza Vaccine Effectiveness in Preventing Hospitalizations in Children. (19th August 2021)

• Record Type: Journal Article
• Authors: Yildirim, Inci; Kao, Carol M; Tippett, Ashley; Suntarattiwong, Piyarat; Munye, Mohamed; Yi, Jumi; Elmontser, Mohnd; Quincer, Elizabeth; Focht, Chris; Watson, Nora; Bilen, Hande; Baker, Julia M; Lopman, Ben; Hogenesch, Elena; Rostad, Christina A; Anderson, Evan J
• Is Part Of: Clinical infectious diseases. Volume 73:Number 10(2021)
• Page Start: 1759
• Page End: 1767
• Publication Date: 2021-08-19
• Subjects: adolescent -- immunization -- influenza vaccine effectiveness -- pediatric; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciab709
• Languages: English
• ISSNs: 1058-4838

Abstract

Abstract: Background: Vaccination is the primary strategy to reduce influenza burden. Influenza vaccine effectiveness (VE) can vary annually depending on circulating strains. Methods: We used a test-negative case-control study design to estimate influenza VE against laboratory-confirmed influenza-related hospitalizations among children (aged 6 months–17 years) across 5 influenza seasons in Atlanta, Georgia, from 2012–2013 to 2016–2017. Influenza-positive cases were randomly matched to test-negative controls based on age and influenza season in a 1:1 ratio. We used logistic regression models to compare odds ratios (ORs) of vaccination in cases to controls. We calculated VE as [100% × (1 – adjusted OR)] and computed 95% confidence intervals (CIs) around the estimates. Results: We identified 14 596 hospitalizations of children who were tested for influenza using the multiplex respiratory molecular panel; influenza infection was detected in 1017 (7.0%). After exclusions, we included 512 influenza-positive cases and 512 influenza-negative controls. The median age was 5.9 years (interquartile range, 2.7–10.3), 497 (48.5%) were female, 567 (55.4%) were non-Hispanic Black, and 654 (63.9%) children were unvaccinated. Influenza A accounted for 370 (72.3%) of 512 cases and predominated during all 5 seasons. The adjusted VE against influenza-related hospitalizations during 2012–2013 to 2016–2017 was 51.3% (95% CI, 34.8% to 63.6%) and varied by season. Influenza VE was 54.7% (95% CI, 37.4% to 67.3%) for influenza A and 37.1% (95% CI, 2.3% to 59.5%) for influenza B. Conclusions: Influenza vaccination decreased the risk of influenza-related pediatric hospitalizations by >50% across 5 influenza seasons. Abstract : A test-negative case-control study estimated inactivated influenza vaccine effectiveness after adjustment at 51.3% (95% confidence interval, 34.8% to 63.6%) against laboratory-confirmed influenza-related hospitalizations among children across 5 influenza seasons in Atlanta, Georgia.