Allergy to IXIARO and BIKEN Japanese Encephalitis Vaccines


Corresponding Author: Andrew D. McCallum, MRCP, Specialty Registrar in Infectious Diseases, Regional Infectious Diseases Unit, Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK. E-mail:


We describe an allergic reaction to both mouse brain-derived BIKEN and Vero cell-derived IXIARO Japanese encephalitis (JE) vaccines in a single traveler. In the absence of the stabilizers and murine proteins in the BIKEN vaccine, a common factor in both vaccines is likely to be responsible, possibly JE virus antigen itself.