Flu vaccination may result in a slight increased risk of developing Guillain-Barré syndrome, according to a Canadian study. Researchers looked at rates of hospital admission due to Guillain-Barré syndrome in Ontario between 1993 and 2004.
The researchers found that, of the 1,601 cases identified, 269 had been vaccinated against influenza within the prior 43 weeks. Vaccination was associated with a 50 per cent increased risk of hospitalisation for Guillain-Barré syndrome. It was 1.5 times as high in those who had been vaccinated as in others (Arch Intern Med 2006; 166: 2,217-21).