Influenza: is live attenuated vaccine safe in children with underlying conditions?

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  • No increased risk for all-cause hospitalization after live attenuated influenza vaccine (LAIV) receipt among children with nonasthma, nonimmunocompromising underlying medical conditions compared with healthy children.

Why this matters

  • Original clinical trials for LAIV excluded children with underlying conditions, but these findings support its safety in children with nonasthma, nonimmunocompromising conditions.

Study design

  • MarketScan Commercial Claims Databases used to identify children aged 2-18 y who received LAIV (2010-2012), including those with underlying medical conditions.
  • Primary outcome: all-cause hospitalization within 14 d of vaccination.
  • Funding: Centers for Disease Control and Prevention.

Key results

  • 1,216,123 children vaccinated, 99,208 with underlying medical conditions (excluding asthma, hemoglobinopathies, malignancy, pregnancy, HIV/AIDS, and non-HIV immunodeficiencies).
  • 642 hospitalizations within observation period.
  • Pneumonia and acute appendicitis most common reasons for hospitalization (10.4% and 5.9%, respectively).
  • No increased risk for hospitalization among children with and without underlying medical conditions.


  • Included only commercially insured children.
  • Limited to database information, no chart reviews.
  • No evaluation of medically attended events not requiring hospitalization.