What is Guillain Barre Syndrome (GBS) and do we expect an increased number of cases following 2009 H1N1 vaccination?
GBS is an acute, bilateral and relatively symmetric weakness/paralysis of the limbs that may involve respiratory and cranial nerve-innervated muscles. GBS occurs worldwide at an annual incidence of 1-2 cases per 100,000. The death rate for GBS is about 4-15%. In most cases, the weakness reaches a peak between 12 hours and 28 days, followed by plateau and subsequent improvement. Despite modern treatment, up to 20% of survivors are disabled after one year. In February 1976, influenza virus isolates from two Army recruits at Fort Dix, New Jersey were identified as a new influenza A strain, the “swine flu”. Eventually 45 million Americans received the swine flu vaccine in 1976. Following vaccination, there was a small increased chance of GBS of about 1 more case per 100,000 people vaccinated. Since 1976, many studies have been done to see if other flu vaccines may cause GBS. Two studies showed one additional case of GBS per 1,000,000 persons vaccinated, while the majority of studies showed
