Safety and immunogenicity of a live attenuated Japanese encephalitis chimeric virus vaccine (IMOJEV®) in children

Area of Science:

• Virology
• Immunology
• Vaccinology

Background:

• Japanese encephalitis is a serious mosquito-borne viral disease prevalent in South-East Asia.
• JE-CV (IMOJEV®) is a live attenuated vaccine against Japanese encephalitis, developed using yellow fever virus as a vector.
• The vaccine utilizes genetic material from the Japanese encephalitis SA14-14-2 strain.

Purpose of the Study:

• To review clinical trial data for the JE-CV vaccine in children up to six years of age.
• To assess the immunogenicity and safety of JE-CV following primary and booster immunization.
• To evaluate the durability of the antibody response and long-term protection.

Main Methods:

• Review of clinical trials conducted in South-East Asian countries.
• Analysis of antibody responses (seroprotection) after single primary and booster doses.
• Assessment of vaccine safety and reactogenicity profiles.
• Modeling of long-term antibody persistence.

Main Results:

• Single-dose primary immunization elicits strong and persistent antibody responses.
• Booster vaccination further enhances and sustains antibody levels.
• 97% of children remained seroprotected up to five years post-booster vaccination.
• Models predict a median protection duration of approximately 30 years after a booster dose.
• JE-CV demonstrated safety and reactogenicity profiles comparable to other routine childhood vaccines.

Conclusions:

• JE-CV is an effective vaccine for Japanese encephalitis prevention in young children.
• The vaccine induces robust and durable immunity, offering long-term protection.
• JE-CV presents a favorable safety profile for pediatric use in endemic regions.