Influenza vaccinations and chemosensory function.

Background: Although influenza vaccines have saved millions of lives, some have been associated with extremely rare adverse effects such as Guillain-Barré syndrome, Bell's palsy, and optic neuritis. Despite the fact that olfactory loss after an influenza vaccination is noted in one case report, no quantitative olfactory testing was performed. Hence, it is unclear whether, in fact, olfactory dysfunction can be associated with such vaccinations.