Nasal flu vaccine linked to Bell's palsy
Reported by Susan Aldridge, PhD, medical journalist
Source: Health and Age

A nasal spray flu vaccine used in Switzerland has been linked to a big increase in the risk of Bell’s palsy.
Many people would rather have a vaccine administered by nasal spray rather than injection. There’s much research going on into these drug delivery methods but, as a new study shows, they may also be linked to unanticipated problems.

During the flu season of 2000-2001, a flu vaccine in the form of a nasal spray was used in Switzerland. Drug monitoring studies showed that the vaccine might increase the risk of a neurological condition called Bell’s palsy. Accordingly, researchers at the University of Zurich and the United States Centers for Disease Control and Prevention looked into this, comparing people with Bell’s palsy with healthy controls. The intranasal flu vaccine had been used by 27 per cent of those in the Bell’s palsy group, compared to just one per cent of controls. This suggests that the vaccine significantly increases the risk of Bell’s palsy. The researchers say it is a component of the vaccine called the adjuvant which causes the hazard, not the active ingredient. It may be that the adjuvant activates dormant herpes virus and this leads to Bell’s palsy. These findings should be borne in mind during further development of nasal spray vaccines.

Source
New England Journal of Medicine 26th February 2004 Volume 350 pages 896-903