Guillain-Barré syndrome (GBS) is an acute, immune-mediated paralytic disorder of the peripheral nervous system.1 Concerns about the risk of developing GBS following influenza vaccination have been present since an association was first noticed during the 1976-1977 A/New Jersey (“swine influenza”) season.2 A statistically significant elevated risk of GBS was found in swine flu vaccinees relative to nonvaccinees within 6 to 8 weeks after vaccination.3-7 Evidence for a relationship between GBS and other influenza vaccines, however, is less clear.8 After 1977, most studies of GBS and influenza vaccines found low relative risks that were not statistically significant.9-12 A study of the 1992-1993 and 1993-1994 seasons found a combined relative risk for GBS among influenza vaccine recipients of 1.7 (95% confidence interval, 1.0-2.8; P = .04) during the 6 weeks following vaccination.13