title: Influenza vaccine effectiveness against hospitalisation with influenza in adults in Australia in 2014.
abstract: We provide estimates of the influenza vaccine protection against hospitalisation with laboratory-confirmed influenza in the 2014 Australian season where the A/H1N1/pdm09 strain predominated. This was performed using a case-test negative study design as part of a national sentinel surveillance system in Australia. Vaccine effectiveness was estimated as (1-OR)×100% where the odds ratio of vaccination in cases vs test negative participants was estimated from a conditional logistic regression. Between April and November, 1692 adult patients were admitted with laboratory-confirmed influenza. Vaccine effectiveness was estimated from 1283 patients with influenza and 1116 test negative patients where vaccination status was ascertained. Vaccination was associated with a reduction in the risk of hospitalisation with influenza of 51.5% (95% CI: 41.6%, 59.7%) in all patients, and a reduction of 50.7% (95% CI: 40.1%, 59.3%) in the target population for vaccination. We estimate that the influenza vaccine was moderately protective against hospitalisation with laboratory-confirmed influenza during the 2014 influenza season in Australia.
authors.affiliation: Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, VIC, Australia; Infection Prevention and Healthcare Epidemiology Unit, Alfred Health, Melbourne, VIC, Australia. Electronic address: allen.cheng@monash.edu.
authors.forename: Allen C
authors.initials: AC
authors.lastname: Cheng
authors.affiliation: Department of Allergy, Immunology and Respiratory Medicine, Alfred Health and Monash University, Melbourne, VIC, Australia.
authors.forename: Tom
authors.initials: T
authors.lastname: Kotsimbos
authors.affiliation: ACT Health Directorate, Canberra, Australia.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Kelly
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001315:Australia / Q000453:epidemiology; D005260:Female; D006760:Hospitalization; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000276:immunology; D007252:Influenza Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000473:pathology / Q000517:prevention & control*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D018570:Risk Assessment; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D007252:Influenza Vaccines
keywords: Hospitalisation; Influenza vaccination; Test negative design; Vaccine effectiveness