Effectiveness of influenza vaccination in working-age adults with diabetes: a population-based cohort study

Thorax. 2013 Jul;68(7):658-63. doi: 10.1136/thoraxjnl-2012-203109. Epub 2013 Mar 27.


Background: Guidelines recommend influenza vaccinations in all diabetic adults, but there is limited evidence to support vaccinating working-age adults (<65 years) with diabetes. We examined the effectiveness of influenza vaccine in this subgroup, compared with elderly adults (≥ 65 years) for whom vaccination recommendations are well accepted.

Methods: We identified all adults with diabetes, along with a sample of age-matched and sex-matched comparison subjects without diabetes, from 2000 to 2008, using administrative data from Manitoba, Canada. With multivariable Poisson regression, we estimated vaccine effectiveness (VE) on influenza-like illnesses (ILIs), pneumonia and influenza (PI) hospitalisations and all-cause (ALL) hospitalisations during periods of known circulating influenza. Analyses were replicated outside of influenza season to rule out residual confounding.

Results: We included 543 367 person-years of follow-up, during which 223 920 ILI, 5422 PI and 94 988 ALL occurred. The majority (58%) of adults with diabetes were working age. In this group, influenza vaccination was associated with relative reductions in PI (43%, 95% CI 28% to 54%) and ALL (28%, 95% CI 24% to 32%) but not ILI (-1%, 95% CI -3% to 1%). VE was similar in elderly adults for ALL (33-34%) and PI (45-55%), although not ILI (12-13%). However, similar estimates of effectiveness were also observed for all three groups during non-influenza control periods.

Conclusions: Working-age adults with diabetes experience similar benefits from vaccination as elderly adults, supporting current diabetes-specific recommendations. However, these benefits were also manifest outside of influenza season, suggesting residual bias. Vaccination recommendations in all high-risk adults would benefit from randomised trial evidence.

Keywords: Clinical Epidemiology; Viral infection.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Diabetes Mellitus / epidemiology*
  • Female
  • Follow-Up Studies
  • Humans
  • Influenza Vaccines / administration & dosage*
  • Influenza, Human / complications
  • Influenza, Human / epidemiology
  • Influenza, Human / prevention & control*
  • Male
  • Manitoba / epidemiology
  • Middle Aged
  • Morbidity / trends
  • Population Surveillance / methods*
  • Prognosis
  • Retrospective Studies
  • Survival Rate / trends
  • Time Factors
  • Vaccination / methods*
  • Young Adult


  • Influenza Vaccines