Gelatin-induced urticaria and anaphylaxis after tick-borne encephalitis vaccine.

Sir, Tick-borne encephalitis (TBE) is a rare disease, acquisition of which occurs only in well-known endemic areas, such as south-western Germany, Austria and Switzerland, through the bites of infected ticks. The course of the disease is not trivial: 0.5 ± 2% of cases are fatal, 2.7% have persistent serious paralysis and some 33% a postencephalitic syndrome. Since there is no speci®c treatment for TBE, immunoprophylaxis is used in endemic areas for controlling this disease. Active immunization has been shown to be effective and safe. Only a few mild side-effects have been reported (1). Allergic reactions to vaccines occur in approximately 0.001 ± 1% of cases (2) and most important antigens are preservatives, rarely antibiotics, culture media substances from the production process or reagents used for inactivation, stabilizers or absorbents (2). Allergic reactions to vaccines are localized mainly to the application site, whereas the onset of systemic anaphylaxis is extremely rare.