The burden of influenza in England by age and clinical risk group: a statistical analysis to inform vaccine policy

J Infect. 2014 Apr;68(4):363-71. doi: 10.1016/j.jinf.2013.11.013. Epub 2013 Dec 1.


Objectives: To assess the burden of influenza by age and clinical status and use this to inform evaluations of the age and risk-based influenza vaccination policy in the United Kingdom.

Methods: Weekly laboratory reports for influenza and 7 other respiratory pathogens were extracted from the national database and used in a regression model to estimate the proportion of acute respiratory illness outcomes attributable to each pathogen.

Results: Influenza accounted for ∼10% of the attributed respiratory admissions and deaths in hospital. Healthy children under five had the highest influenza admission rate (1.9/1000). The presence of co-morbidities increased the admission rate by 5.7 fold for 5-14 year olds (from 0.1 to 0.56/1000), the relative risk declining to 1.8 fold in 65+ year olds (from 0.46 to 0.84/1000). The majority (72%) of influenza-attributable deaths in hospital occurred in 65+ year olds with co-morbidities. Mortality in children under 15 years was low with around 12 influenza-attributable deaths in hospital per year in England; the case fatality rate was substantially higher in risk than non-risk children. Infants under 6 months had the highest consultation and admission rates, around 70/1000 and 3/1000 respectively.

Conclusions: Additional strategies are needed to reduce the remaining morbidity and mortality in the high-risk and elderly populations, and to protect healthy children currently not offered the benefits of vaccination.

Keywords: Disease burden; Influenza; Modelling; Policy; Regression; Vaccination.

MeSH terms

  • Adolescent
  • Adult
  • Age Factors
  • Aged
  • Aged, 80 and over
  • Child
  • Child, Preschool
  • England / epidemiology
  • Female
  • Health Policy
  • Humans
  • Infant
  • Infant, Newborn
  • Influenza Vaccines / administration & dosage*
  • Influenza, Human / epidemiology*
  • Influenza, Human / mortality
  • Influenza, Human / prevention & control*
  • Male
  • Middle Aged
  • Prevalence
  • Risk Factors
  • Survival Analysis
  • Young Adult


  • Influenza Vaccines