TABLE 2

Percentage Vaccinated Among Influenza-Associated Pediatric Deaths Compared With NIS-Flu Cohorts, With VE Estimates by Season and Age Group

StratumInfluenza-Associated DeathsaNIS-FlubVEc
No. Vaccinated/Total% VaccinatedAverage % Vaccinated (LCL, UCL)%95% CI
Overall75/2912648(42, 55)6554 to 74
Age
 6 mo–4 y31/933355(47, 62)6140 to 76
 5–12 y26/1282050(44, 56)7663 to 85
 13–17 y18/702636(30, 43)400 to 67
Season
 2010–201122/733047(39, 55)5422 to 74
 2011–20124/211951(44, 59)8041 to 95
 2012–201328/1162446(39, 52)6446 to 77
 2013–201421/812653(47, 58)7152 to 83
Influenza virus
 Influenza A44/1732548(41 55)6653 to 76
 Influenza B31/1132749(42, 55)6242 to 75
  • LCL, lower 95% confidence limit; UCL, upper 95% confidence limit; CI, credible interval.

  • a Excludes cases with unknown vaccination status.

  • b Average influenza vaccine coverage estimates (with lower and upper 95% confidence limits) for NIS-Flu comparison cohorts, paired by season, age category, and state of residence with pediatric deaths, during month ending >14 d before case illness onset.

  • c VE calculated as 100 × (1 − OR) from logistic regression comparing odds of vaccination among influenza-associated deaths to odds of vaccination in NIS-Flu comparison cohorts, with Bayesian 95% CIs.