Adverse events following influenza A (H1N1) 2009 monovalent vaccines reported to the Vaccine Adverse Event Reporting System, United States, October 1, 2009-January 31, 2010

Vaccine. 2010 Oct 21;28(45):7248-55. doi: 10.1016/j.vaccine.2010.09.021. Epub 2010 Sep 16.


The United States (US) influenza A (H1N1) 2009 monovalent (2009-H1N1) vaccination program began in October 2009. Reports to the vaccine adverse event reporting system (VAERS), a US spontaneous reporting system, were reviewed to identify potential rare events or unusual adverse event (AE) patterns after 2009-H1N1 vaccination. The adverse event profile after 2009-H1N1 vaccine in VAERS (∼10,000 reports) was consistent with that of seasonal influenza vaccines, although the reporting rate was higher after 2009-H1N1 than seasonal influenza vaccines, this may be, at least in part, a reflection of stimulated reporting. Death, Guillain-Barré syndrome and anaphylaxis reports after 2009-H1N1 vaccination were rare (each <2 per million doses administered).

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adolescent
  • Adult
  • Adverse Drug Reaction Reporting Systems / statistics & numerical data*
  • Aged
  • Child
  • Child, Preschool
  • Data Mining
  • Female
  • Humans
  • Infant
  • Influenza A Virus, H1N1 Subtype
  • Influenza Vaccines / adverse effects*
  • Influenza, Human / prevention & control*
  • Male
  • Middle Aged
  • Product Surveillance, Postmarketing / methods
  • United States
  • Vaccination / adverse effects
  • Vaccination / statistics & numerical data
  • Young Adult


  • Influenza Vaccines