Strategies for the Development of New Vaccines

S.A. Plotkin
2010 International Journal of Infectious Diseases  
Abstracts e171 with permanent sequelae such as cognitive or neuropsychiatric complaints, dysphasia, hearing defects and spinal paralysis. The severity of the disease and the lack of causal therapy emphasize the need for prevention of tick borne encephalitis (TBE) by vaccination. Inactivated, whole virus TBE vaccines (FSME IMMUN, Baxter and Encepur, Novartis) are widely used in Europe. In recent years a full clinical development program, including safety, immunogenicity and seropersistence
more » ... ropersistence studies has been conducted for FSME-IMMUN in all age groups. Antigen doses of 2.4 g and 1.2 g were identified as optimal for adults and children, respectively. In an ongoing study, the safety and immunogenicity of FSME-IMMUN 0.25 ml Junior and Encepur 0.25 ml Children are being investigated in children 1 to 11 years of age. A total of 150 and 152 subjects were enrolled in the FSMEIMMUN and Encepur group, respectively. Immunogenicity was assessed by two different ELISA assays using antigens homologous to the TBEV strains of either FSME IMMUN (IMMUNOZYM 1 ), or Encepur (Enzygnost 2 ). Four weeks after the second vaccination, in the FSME-IMMUN group, 100% of subjects were seropositive in both the IMMUNOZYM-(>126 VIEU/ml) and the Enzygnost ELISA (>10.32U/ml) compared with 94.0% and 96.7% respectively, in the Encepur group. Geometric mean concentrations (GMC) measured by IMMUNOZYM ELISA were 3026 in the FSME-IMMUN and 678 in the Encepurgroup. GMCs measured with the Enzygnost ELISA were 163.3 (FSME-IMMUN) and 93.7 (Encepur). Local reactions after the 1st vaccination occurred in 12.7% with FSME-IMMUN and in 28.9% with Encepur. The rate of systemic reactions was comparable: 9.3% (FSME-IMMUN) and 11.8% (Encepur). The presently marketed TBE vaccines represent highly effective tools for the prevention of this continuously spreading disease.
doi:10.1016/j.ijid.2010.02.1863 fatcat:23i7j2xh65gfjdzu5h4jhhojjm