Guillain-Barré syndrome

Guillain-Barré syndrome (GBS) is an autoimmune disorder that degrades the peripheral nervous system. While it is primarily caused by an acute infection, it has been linked by some studies to vaccines and is a favorite of the anti-vaccination crowd. Most people hospitalized with GBS will recover fully within a few weeks, although a rare number of cases may result in permanent disability and a tiny fraction are fatal.

Guillain-Barré syndrome and vaccines
The link to vaccinations emerged during the 1976 swine flu outbreak, when a reported 500 cases of GBS were thought to have a causal link to the administration of the vaccine. Several major epidemiological studies over the next few years examined the risk of GBS carefully and found no significant rise in incidences compared to people not vaccinated. There did appear to be a slight increase in risk from the 1976 flu vaccine but the manufacturing process and preservative changes instituted after the discovery of the link seemed to have eliminated the risk.

Research has continued off and on over the intervening decades and modern flu vaccines show no significant pattern of an increased risk of Guillain-Barré syndrome.

Guillain-Barré syndrome and the anti-vaccination movement
GBS has been a favorite scare tactic of the anti-vaccine movement for years. There appears to be support that a slight increase in risk to GBS was associated with the vaccine used in 1976. This risk factor is extrapolated to be proof that any negative claim of vaccines ever made also has to be true. The anti-vaccination movement also loves to focus on the extremely rare fatalities of the disease and play it up as the most likely consequence of getting vaccinated.

In 2009, a swine flu pandemic increased public demand for a major vaccine program. A letter sent out to a neurologist describing the 1976 incident with GBS was leaked to the press, creating mild panic. The letter only referred to the reported cases in the 1976 vaccine program. There was no new information linking the specific vaccine for 2009 to GBS. The 30 years of subsequent research that has shown that improvements to vaccine production and preservation have eliminated the risk was not part of the media coverage.