Safety and immunogenicity of the modified adult tick-borne encephalitis vaccine FSME-IMMUN: results of two large phase 3 clinical studies.

Abstract

A prospective, randomised, multicentre, single-blind phase 3 study was performed to assess the safety of a vaccination schedule consisting of two vaccinations (21-35 days apart) with the tick-borne encephalitis (TBE) vaccine FSME-IMMUN "adults" (five consecutive lots) in comparison to another licensed TBE vaccine (Encepur), with polygeline) (two lots) in healthy volunteers (n=3966) aged 16-65 years. The safety of the third vaccination with FSME-IMMUN "adults" (6 months after the first vaccination) was investigated in a follow-up study on the same population (n=3705) and TBE antibody titres were analysed pre- and post-vaccination in a subgroup of volunteers (n=564). Following the first vaccination, the overall incidence of fever (> or =38.0 degrees C) was 0.8% in the FSME-IMMUN "adults" study group and 5.6% in the comparator study group; fever was mainly mild. The fever rate after the second vaccination was 0.6% and 0.5% in the two study groups, respectively. Local and systemic reactions after the first vaccination occurred with a lower frequency in the FSME-IMMUN "adults" study group than in the comparator group. Upon analysing the tolerability of the third vaccination with FSME-IMMUN "adults", similar results were determined in both study groups of volunteers previously vaccinated with FSME-IMMUN "adults" or with the comparator vaccine. The immunogenicity results demonstrated similar seroconversion rates (as determined by ELISA or neutralization test) before and after the third vaccination in the FSME-IMMUN "adults" group and in the comparator group respectively. The results of both studies demonstrate that: (1) FSME-IMMUN "adults" is safe and highly immunogenic, (2) all five production lots of FSME-IMMUN "adults" were consistent with respect to a low rate of adverse events, (3) FSME-IMMUN "adults" induces considerably lower adverse reaction rates than the comparator vaccine after the first vaccination, and (4) two vaccinations with the comparator vaccine can be successfully followed by a third vaccination with FSME-IMMUN "adults".

• Authors: A Loew-Baselli, R Konior, B G Pavlova, S Fritsch, E Poellabauer, F Maritsch, P Harmacek, M Krammer, P N Barrett, H J Ehrlich, FSME-IMMUN study group
• Journal: Vaccine (Vaccine) Vol. 24 Issue 24 Pg. 5256-63 (Jun 12 2006) ISSN: 0264-410X [Print] Netherlands
• PMID: 16624457 (Publication Type: Clinical Trial, Phase III, Journal Article, Multicenter Study, Randomized Controlled Trial)

Chemical References

• Antibodies, Viral
• Viral Vaccines

Topics

• Adolescent
• Adult
• Aged
• Antibodies, Viral (blood)
• Encephalitis Viruses, Tick-Borne (immunology)
• Female
• Humans
• Male
• Middle Aged
• Single-Blind Method
• Vaccination
• Viral Vaccines (adverse effects, immunology)