Childhood influenza: number needed to vaccinate to prevent 1 hospitalization or outpatient visit.
OBJECTIVE
The goal was to assess the potential benefits of the influenza vaccine recommendations for children 6 to 59 months of age by estimating the number of children needed to be vaccinated to prevent 1 hospitalization or 1 outpatient visit attributable to influenza.


METHODS
The influenza burden was obtained from published studies in which rates for children 6 to 23 months and 24 to 59 months of age could be ascertained. We assumed a range of influenza vaccine efficacies of 25% to 75%, consistent with the literature. We estimated the number of children who needed to be vaccinated to prevent 1 influenza-attributable hospitalization or 1 outpatient visit for each age group.


RESULTS
As both vaccine efficacy and severity of the influenza season increased, the number of children who needed to be vaccinated to prevent 1 hospitalization or 1 outpatient visit decreased. The numbers of children who needed to be vaccinated to prevent 1 hospitalization in a year with 50% vaccine efficacy ranged from 1031 to 3050 for children 6 to 23 months of age and from 4255 to 6897 for children 24 to 59 months of age. For every 12 to 42 children 6 to 59 months of age vaccinated in a year with 50% vaccine efficacy, we estimated that 1 influenza-attributable outpatient visit would be prevented.


CONCLUSIONS
With 1 outpatient visit being prevented through vaccination of <50 children, influenza vaccination can reduce influenza-attributable medical visits in children significantly, even in years with modest vaccine efficacy.
Lewis
Elizabeth N
EN
Vanderbilt University Medical School, Nashville, Tennessee, USA.
Griffin
Marie R
MR
Szilagyi
Peter G
PG
Zhu
Yuwei
Y
Edwards
Kathryn M
KM
Poehling
Katherine A
KA
D017677:Age Distribution; D000554:Ambulatory Care Facilities / Q000706:statistics & numerical data*; D002675:Child, Preschool; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D007223:Infant; D007252:Influenza Vaccines; D007251:Influenza, Human / Q000517:prevention & control*; D014481:United States
D007252:Influenza Vaccines