The Population Impact of a Large School-Based Influenza Vaccination Campaign

Details

• Alternative Title:
  PLoS One
• Personal Author:
  Grijalva, Carlos G. ; Zhu, Yuwei ; Simonsen, Lone ; Mitchel, Edward ; Griffin, Marie R.
• Description:
  Background
  
  The optimal vaccination strategy to mitigate the impact of influenza epidemics is unclear. In 2005, a countywide school-based influenza vaccination campaign was launched in Knox County, Tennessee (population 385,899). Approximately 41% and 48% of eligible county children aged 5–17 years were immunized with live attenuated influenza vaccine before the 2005–2006 and 2006–2007 influenza seasons, respectively. We sought to determine the population impact of this campaign.
  
  Methods
  
  Laboratory-confirmed influenza data defined influenza seasons. We calculated the incidence of medically attended acute respiratory illness attributable to influenza in Knox and Knox-surrounding counties (concurrent controls) during consecutive seasons (5 precampaign and 2 campaign seasons) using negative binomial regression and rate difference methods. Age-stratified analyses compared the incidence of emergency department (ED) visits and hospitalizations attributable to influenza.
  
  Results
  
  During precampaign seasons, estimated ED visit rates attributable to influenza were 12.39 (95% CI: 10.34–14.44) per 1000 Knox children aged 5–17 years and similar in Knox-surrounding counties. During the campaign seasons, annual Knox influenza-associated ED visit rates declined relative to rates in Knox-surrounding counties: rate ratios 0.55 (95% CI: 0.27–0.83) and 0.70 (95% CI: 0.56–0.84) for the first and second campaign seasons, respectively. Overall, there were about 35% or 4.86 per 1000 fewer influenza-associated ED visits among Knox County children aged 5–17 years attributable to the campaign. No significant declines in Knox compared to surrounding counties were detected for influenza associated ED visits in children aged <5 years, all adults combined or selected adult age subgroups, although power for these analyses was limited. Alternate rate-difference analyses yielded consistent results.
  
  Conclusion
  
  Vaccination of approximately 45% of Knox school-aged children with influenza vaccine was associated with a 35% annual reduction (4.86 per 1000) in ED visit rates attributable to influenza. Higher vaccination coverage and/or larger studies would be needed to determine whether similar interventions have indirect benefits in other age groups.
  
  
• Subjects:
  Adolescent Adult Aged Child Child, Preschool Emergency Service, Hospital Female Hospitalization Humans Immunization Programs Incidence Influenza, Human Influenza Vaccines Male Medicine Middle Aged Program Evaluation Research Article Respiration Disorders Schools Seasons Vaccination Young Adult

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• Source:
  PLoS One. 5(11).
• Pubmed ID:
  21209872
• Pubmed Central ID:
  PMC3013075
• Document Type:
  Journal Article
• Funding:
  K01 IP000163/IP/NCIRD CDC HHS/United States
• Place as Subject:
  Tennessee
• Volume:
  5
• Issue:
  11
• Collection(s):
  CDC Public Access
• Main Document Checksum:
  urn:sha256:42a72c1506f086f2d24d43a30df9dc49f6f6601b235f14bce937274a6b6fb322
• Download URL:
  https://stacks.cdc.gov/view/cdc/22852/cdc_22852_DS1.pdf
• File Type:
  [PDF - 414.73 KB ]