Influenza A vaccine decreases the incidence of otitis media in 6- to 30-month-old children in day care.

OBJECTIVE

To determine if the use of influenza vaccine in children in day care decreases the incidence of otitis media during the influenza season.

DESIGN

Prospective cohort study.

SETTING

Eight day-care centers in North Carolina.

PARTICIPANTS

One hundred eighty-six children aged 6 to 30 months.

INTERVENTION

Half the participants received trivalent subvirion influenza virus vaccine.

MEASUREMENTS

Acute otitis media (AOM) and serous otitis media (SOM) were assessed biweekly from mid-November 1993 to mid-March 1994 by visual and tympanometric examinations performed by "blinded" observers. The winter season was divided into three periods-before, during, and after influenza season--and the number of children with AOM or SOM during each period was determined. Unadjusted and adjusted odds ratios (ORs) were computed, while controlling for race and sex using logistic regression methods.

RESULTS

Influenza vaccine was protective against AOM (OR = 0.69, 95% CI, 0.49-0.98) during the influenza season. Although there may have been some protection against SOM (OR = 0.75, 95% CI, 0.54-1.02) statistical significance was not achieved. Myringotomy tubes were also significantly protective against AOM and SOM during all three time periods, with ORs between 0.34 and 0.52, but the greatest protection was seen during the influenza period.

CONCLUSIONS

Influenza vaccination of 6- to 30-month-old children in day care was associated with a decreased incidence of otitis media during the influenza season. Myringotomy tubes protected against AOM and SOM during all 16 weeks monitored.