Antibody persistence after two vaccinations with either FSME-IMMUN® Junior or ENCEPUR® Children followed by third vaccination with FSME-IMMUN® Junior

Abstract

Tick-borne encephalitis (TBE) vaccination strategies to induce optimal seroprotection in children are under constant evaluation. This multi-center, randomized, controlled, phase III clinical study examined antibody persistence in children aged 1–11 y following two prospectively administered doses of either the FSME-IMMUN® Junior or Encepur Children® vaccines, as well as investigating the immunogenicity, safety and vaccine interchangeability of a third vaccination with FSME-IMMUN^® Junior. A high level of antibody persistence was observed in all subjects 6 mo after the first of two vaccinations with either pediatric TBE vaccine. Based on both immunological tests and viral antigens used, slightly higher seropositivity rates and higher GMCs /GMTs were found in children vaccinated with FSME-IMMUN® Junior compared with those who received Encepur® Children. Seropositivity rates across all age strata combined six months after the first vaccination with FSME-IMMUN® 0.25 mL Junior were 95.1% as determined by Immunozym ELISA, 93.2% as determined by Enzygnost ELISA and 95.3% as determined by NT; compared with 62.6%, 80.5% and 91.0% respectively after vaccination with Encepur® Children. A third vaccination with FSME-IMMUN^® Junior induced 100% seropositivity in both study groups and was well tolerated as demonstrated by the low rates of systemic and injection site reactions. Subjects who received either FSME-IMMUN Junior® or Encepur^® Children vaccine for the first two vaccinations and FSME-IMMUN Junior® for the third showed a comparably strong immune response regardless of the previous TBE vaccine administered, demonstrating that two vaccinations with Encepur® Children can successfully be followed by a third vaccination with FSME-IMMUN Junior®.

Keywords: :

• Encepur® Children
• FSME-IMMUN® Junior
• Tick-borne encephalitis
• pediatric vaccines

Conflict of Interest

E.M. Poellabauer, B.G. Pavlova, A. Loew-Baselli, S. Fritsch, A. Geisberger, P.N. Barrett and H. J. Ehrlich are Baxter employees and have received Baxter stocks and stock options. R. Prymula and R. Angermayr have received consulting fees for the conduct of the present and other clinical studies from Baxter.

Acknowledgments

The authors wish to thank all the investigators (Johannnes Neugebauer, MD; Austria and Vladimir Nemec, MD; Drahoslava Lévová, MD; Vera Hvizd’alová, MD; Iva Madejová, MD; Irena Válova, MD; Jana Krausova MD; Pavel Kosina, MD; Vera Ryvolová MD; Czech Republic) who conducted this study. The authors wish to thank the Baxter Clinical Study Team: David Perry, Barbara Valenta-Singer, Jael Bosman, Peter Harmacek, Ulrike Langhammer-Augustin, Wolfgang Draxler, Karima Benamara, and Jennifer Doralt for their contribution to the success of this study.