ACUTE DISSEMINATED ENCEPHALOMYELITIS AFTER TREATMENT WITH JAPANESE B ENCEPHALITIS VACCINE (NAKAYAMA-YOKEN AND BEIJING STRAINS)

Seven children with acute disseminated encephalomyelitis (ADEM) after treatment with Japanese B encephalitis vaccine (JBEV) (Nakayama-Yoken strain 1968-88 and Beijing strain 1989-93) were identified by mailed q uestionnaires and by compilation of previously published case reports. It was considered that encephalomyelitis might have been related to v accine treatment as the vaccine is derived from mouse brain tissue inf ected with Japanese B encephalitis virus, a potentially cross reactive antigen. The incidence of severe neurological complications associate d with the newer Japanese B encephalitis Beijing strain vaccine seemed to be less than one case per 1 000 000, which is similar to the incid ence of neurological complications associated with the older Nakayama- Yoken strain vaccine.