Does influenza vaccination improve pediatric asthma outcomes?

OBJECTIVE

Controversy exists regarding the effectiveness of influenza vaccination in preventing influenza-related asthma exacerbations in the pediatric population. While yearly influenza immunization is widely recommended for children with asthma, there is currently little evidence to support this practice. Several studies have demonstrated no measurable benefit in asthma outcomes. This study sought to determine whether influenza vaccination status is associated with indicators of asthma morbidity within the military pediatric population.

METHODS

A survey was conducted of patients 3 to 18 years of age with a diagnosis of asthma enrolled in the pediatric clinics of Brooke Army Medical Center, Fort Sam Houston, Texas, and Wilford Hall Medical Center, Lackland Air Force Base, Texas. Management practices and outcomes for 80 children were evaluated. Data were analyzed using the statistical package SPSS version 12 (SPSS Inc., Chicago). Univariate analyses were performed to identify associations between influenza vaccination, selected demographic variables and asthma exacerbation defined by oral steroid prescription, hospital visits, and unscheduled clinic or emergency department visits for asthma symptoms. Logistic regression analyses were conducted to detect possible confounding variables.

RESULTS

In the univariate analyses, current influenza vaccination status was associated with a significant reduction of oral steroid use in the 12 months before the survey. This relationship was appreciated to a lesser extent with emergency department or unscheduled clinic visits in the last 12 months. No significant differences were found regarding the distribution of influenza vaccination status across selected demographic variables. In the multivariate analyses, current influenza vaccination status was independently associated with significantly decreased odds of using oral steroids in the previous 12 months. There was no evidence of confounding or effect modification.

CONCLUSIONS

This study suggests influenza vaccination is associated with fewer asthma exacerbations. After controlling for several potential confounding variables, administration of influenza vaccine was associated with a protective effect against indicators of asthma exacerbations. Our results indicate that children with asthma in the military beneficiary population may benefit from annual influenza vaccination.