DISCUSSION

YEL has been considered as one of the safest vaccine, with a very low incidence of adverse events. The risk of vaccine-associated neurotropic (YEL-AND) disease has been estimated as less than 8 per 1,000,000 persons 1, 2. Recent reports of post-vaccinal encephalitis suggest that onset of neurological symptoms may occur up to 30 days after vaccination. Clinically, YEL-AND might present as encephalitis, meningoencephalitis, myelitis, acute disseminated encephalomyelitis (ADEM), retrobulbar optic neuritis, seizures, cranial neuropathies, headaches, vertigo, paresthesias, Guillain-Barre syndrome (GBS), Fisher variant of GBS, and recently reported acute hemorrhagic fever among others. Autoimmune involvement of the central and peripheral nervous system have been proposed as a plausible pathophysiological mechanism of the disease 3-5.