Flu shot linked to extremely rare side-effect, Canadian study shows

"It is important for people to know that this is an extremely rare disease and there is a very slight increased risk . . . However, overall the benefits of this vaccine far outweigh any of the risks. And we know that the vaccine prevents 70 to 90 per cent of infections in healthy people."

Not getting vaccinated could lead to a miserable bout of the flu - including aching muscles, respiratory symptoms and fever - that will eventually run its course. But for some people, influenza can be deadly. Each year, between 500 and 1,500 Canadians die from complications of the flu, most of them elderly and young children.

"We know that the vaccine can prevent 80 to 90 per cent of deaths in people over 65 years of age in (long-term care) institutions," Yaffe said.

Contrast that with the small risk of developing Guillain-Barre syndrome, a rare condition that typically affects about 10 per one million people worldwide. The disorder occurs when immune system cells mistakenly attack nerve cells that support the muscles, usually beginning in the legs.

Initial symptoms may include tingling in the feet and weakness in the legs. Untreated, its effects can spread throughout the body. In most severe cases, GBS can lead to paralysis and even death, although the majority of people who develop GBS recover with treatment, Juurlink said.

"This is something that could change or conceivably end someone's life, even though it is extremely, extremely rare. It's therefore something to be aware of," he said. "If they got the vaccine and within a few weeks they start getting these symptoms, they should seek medical attention promptly and get treatment."

The study, published in Monday's issue of the Archives of Internal Medicine, analyzed hospital admission records across Ontario between 1993 and 2004. The researchers identified 1,601 hospital admissions for Guillain-Barre syndrome, 269 of which occurred within 43 weeks of the patient receiving a flu vaccination in October or November.

Patients were about 1.5 times as likely to be hospitalized for GBS in the two to seven weeks after vaccination than they were 20 to 43 weeks later, the study found.

In a second analysis, the researchers looked at the 2,173 hospital admissions due to GBS that occurred between 1991 and 2004 to see if there was any spike in cases after 2000, when universal access to free flu shots began in the province.

Juurlink said no significant difference in the hospitalization rate was found after the immunization program began.

Read the full article here

Broken Link? If the link to the original article is broken or has been altered you can view the article by clicking here.