Seasonal Influenza Vaccine and Increased Risk of Pandemic A/H1N1‐Related Illness: First Detection of the Association in British Columbia, Canada

Abstract

An outbreak investigation in British Columbia during the late spring of 2009 provided the first indication of an unexpected association between receipt of TIV and pH1N1 illness. This led to 5 additional studies through the summer 2009 in Canada, each of which corroborated these initial findings.