NEW YORK (Reuters Health) – There appears to be no temporal association between Guillain-Barre syndrome and influenza vaccination. However, influenza-like illness and Guillain-Barre does show such a link, UK researchers report in the February 1st issue of the American Journal of Epidemiology.
Dr. Julia Stowe of the Health Protection Agency Centre for Infections, London and colleagues observe that evidence for an association between flu vaccination and Guillain-Barre syndrome is conflicting.
To gain further information on the matter, the researchers used the UK general practice database to identify 690 people who had had episodes of the syndrome between 1990 and 2005.
The team found that the relative incidence of Guillain-Barre syndrome within 90 days of influenza vaccination was 0.76. There were similar findings when the analysis was restricted to validated cases (relative incidence, 0.89).
However, the relative incidence within 90 days of a influenza-like illness was 7.35. When the period was reduced to 30 days, this figure rose to 16.64.
“Our study,” the researcher point out, “provides robust evidence that seasonal influenza vaccination does not cause Guillain-Barre syndrome.”
Dr. Stowe told Reuters Health that “it follows that increasing vaccine uptake should lead to a decrease in Guillain-Barre syndrome.”
However, she noted, “The reduction possible would be small, because only about 2% of Guillain-Barre syndrome in our study was estimated to be due to influenza-like illness.”
Am J Epidemiol 2009;169:382-388.