HAMILTON, ON – November 27, 2009 –– Hamilton Public Health Services has received a report of Guillain-Barré Syndrome in a Hamilton adult. Guillain-Barré syndrome (GBS) is an acute illness characterized by sudden onset of weakness or paralysis. Most patients recover fully. Usually Guillain-Barré occurs a few days or weeks after the patient has had symptoms of a respiratory or gastrointestinal viral infection. Influenza infections have been reported as a cause of GBS, and to a lesser extent, influenza vaccination has been rarely associated with such cases.
This case occurred three weeks after the patient received the adjuvanted pandemic H1N1 vaccine. However, the patient also had a mild viral illness approximately 10 days prior to the onset of his GBS symptoms, which may be responsible for this case.
Guillain-Barre Syndrome is a condition which occurs all over the world including in Ontario and has multiple causes, mainly infections, including influenza. This means there is a constant baseline rate of GBS in Ontario. It follows that we expect to find cases occurring in people who are recently vaccinated by coincidence, and this is more likely to be observed when large numbers of people are vaccinated - a temporal rather than casual association.
In collaboration with our provincial counterparts, we have examined the risk of GBS in Ontario. From the information available on pandemic H1N1 vaccine distributed to date in Ontario, we would expect to have seen 1.29-2.15 cases of GBS in Ontario as of November 27 amongst people who have received the pandemic H1N1 vaccine, even if the vaccine doesn’t carry any risk at all of causing this syndrome. We also expect further cases to occur in the province, again just by chance. We are following these cases very closely as part of our evaluation of vaccine safety.
There have been no other cases of GBS reported to data in Ontario in association with the pandemic H1N1 vaccine. This means that while GBS has been reported rarely following influenza vaccination in the past, Ontario data suggests that the pandemic H1N1 vaccine currently in use is not statistically associated with GBS.
This case of GBS was not a severe case, and the patient did not require ventilation. The patient is currently recovering at home.
“Our hearts go out to this patient and family,” says Dr. Chris Mackie, Hamilton’s Associate Medical Officer of Health. “This is a tragic event, but it does not signal a safety concern with this vaccine. It is important to remember that the influenza virus puts you at much greater risk of GBS than the vaccine.”
Symptoms of GBS usually begin with numbness or tingling in the toes and fingers. These symptoms progress over several days with weakness in the arms and legs, and/or a “rubbery” feeling in the legs, which can buckle and may cause difficulty walking. In some people the symptoms do not progress beyond numbness or tingling. Others may experience only mild symptoms, or symptoms on one side of the body. In severe cases, the respiratory muscles can be compromised, and the patient may require ventilation. “There are many potential causes of these symptoms. If you are experiencing neurological symptoms, please consult your doctor,” said Dr. Mackie.
For the latest information on H1N1 flu and clinics or to schedule an appointment, visit Public Health Services website at www.hamilton.ca/H1N1 or call 905-546-H1N1 (4161).
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Media Contact:
Wendy Stewart
Communications Officer
Public Health Services
905 546-2424, ext. 5918