Updated: April 28, 2004
Because of a slight increase in the frequency of Guillain-Barré Syndrome (GBS)—a progressive disorder affecting the nervous system—associated with the 1976 swine flu vaccine, subsequent flu vaccines have been closely monitored.
The IOM’s Immunization Safety Review committee reviewed the data on influenza vaccine and neurological conditions and concluded that the 1976 Swine Influenza vaccine did cause GBS in adults. The evidence about GBS for other years’ influenza vaccines was not clear to establish a causal relationship; hence an association could not be accepted or rejected.
The committee also concluded that the scientific evidence shows that influenza vaccines do not trigger relapses of multiple sclerosis (MS) in adults with the disease.
In addition, the committee reviewed theories on how the influenza vaccine could damage the nervous system. No strong evidence was found that the vaccine could lead to neurological problems in humans. The committee expressed that “without experimental data or evidence from studies in humans, the biological means by which the vaccine could increase a person’s risk of developing GBS or MS through a direct toxic effect on the nervous system are only theoretical.”
Read the full report at: http://www.iom.edu/report.asp?id=15625