Safety and Immunogenicity of JECEVAX in Young Children

Overview

A dose escalating study with 3 different dosing regimens of the studied vaccine (JECEVAX- VABIOTECH-Vietnam) and a licensed vaccine (JEVAX-VABIOTECH-Vietnam) is conducted in Vietnamese children, aged 9 to 24 months to assess the safety and immunogenicity. Two hundred children are enrolled and randomly assigned into 4 groups (50 children/group), each of which receive 2 doses of study / control vaccine subcutaneously, at 10-12 days interval. Safety issues included immediate reaction at the site of injection and systemic reaction within 30 min of administration, solicited and unsolicited adverse events occurs from the first dose to 30 days after second dose; SAE (from start of first dose to 30 days after second dose), blood cell count, urea, ALT, AST. Immunogenicity outcomes include seroconversion of neutralizing antibodies (blood samples are taken prior to 1st dose and 20-22 days post 2nd dose).

Mouse brain-derived Japanese Encephalitis (JE) vaccine was developed in Vietnam since 1989 with the support from WHO and BIKEN institute, Japan. It helped Viet Nam prevents Japanese Encephalitis outbreaks successfully during those years. However, mouse brain-derived JE vaccine production requires companies to compliance various requirements from WHO. Especially, WHO has a plan to replace the mouse brain-derived JE vaccines with Cell culture-derived JE vaccines. Vero cell-derived vaccine technology shows many advantages compares to Mouse brain-derived vaccine technology. VABIOTECH has been approved and sponsored by the Ministry of Science and Technology to produce Vero cell - derived JE vaccine. The vaccine demonstrated a good safety and immunogenicity profile in animal models. The vaccine has been proven safety in volunteer adults. In this study, a dose escalating study with 3 different dosing regimens of the studied vaccine (JECEVAX) and a licensed vaccine (JEVAX-VABIOTECH Vietnam) is conducted in Vietnamese children, aged 9-24 months to assess the safety and immunogenicity. Two hundred children are enrolled and randomly assigned into 4 groups (50 children/group), each of which receive 2 doses of investigate vaccines or control vaccine subcutaneously, at 10-12 days interval. Safety issues included immediate reaction at the site of injection and systemic reaction within 30 min of administration, solicited and unsolicited adverse events occurs from the first dose to 30 days after second dose; SAE (from start of first dose to 30 days after second dose), blood cell count, urea, ALT, AST. Immunogenicity outcomes include seroconversion of neutralizing antibodies (blood samples are taken prior to 1st dose and 20-22 days post 2nd dose).