Influenza vaccines and Guillain Barre syndrome

Abstract

Guillain Barré syndrome (GBS) is an acute immune-mediated polyradiculopathy affecting children and adults, which usually presents with acute flaccid paralysis. The association of GBS with vaccination first became a major concern during 1976 when an emerging strain of the influenza virus led to a mass immunization campaign to protect against a potential pandemic. The vaccines were associated with a small but significant increase in the risk of GBS in the weeks following vaccination. In subsequent years, there has been increased monitoring of adverse events relating to influenza vaccines. Assessments conducted following the 1976 influenza vaccination campaign have demonstrated either no risk or a slight elevated risk of GBS following seasonal influenza vaccination (approximately one additional case per million vaccinations). This chapter will discuss the scientific evidence to date regarding the association between influenza vaccines and GBS.