Long-term immunity after vaccination against tick-borne encephalitis with Encepur using the rapid vaccination schedule.

148 of 157 invited adult subjects who had participated in previous studies were enrolled in this extension study for evaluation of immunogenicity and safety of the second TBE booster immunization. All subjects had been previously immunized in studies with Chiron's formerly marketed TBE vaccine (containing polygeline as the stabilizer) according to the rapid vaccination schedule (i.e.