Phase III Study to Evaluate Safety and Immune Response of SK Japanese Encephalitis mRNA Vaccines GBP560 in Healthy Adults 18 and Older

What this Trial Is About

Researchers are evaluating the safety, reactogenicity, and immune response of SK Japanese Encephalitis mRNA vaccines GBP560 in healthy adults aged 18 years and older. This 2-stage, Phase III randomized and observer-blinded study compares different doses and formulations of GBP560 with active comparators IXIARO and IMOJEV. The purpose is to understand how the vaccines perform in terms of safety and immune protection against Japanese Encephalitis Virus JEV. Participants receive two doses of the test vaccines or comparators at 4-week intervals. Stage 1 tests low, mid, and high doses 3, 15, and 50 micrograms of GBP560 variants A and B. Active comparators IXIARO and IMOJEV, as well as placebo saline for IMOJEV, are also given in Stage 1 and Stage 2. In Stage 2, participants receive two intramuscular injections aligned with the selected dose regimen from Stage 1. Throughout the study, participants are monitored for immediate reactions, local and systemic side effects, and any adverse events up to 24 months after vaccination. Immune responses are measured using live-virus neutralization tests at multiple time points up to two years after the second dose. Additional assessments include cell-mediated immune responses. The study includes regular visits for vaccinations, safety checks, and blood tests to evaluate the vaccines impact on immune protection and safety in healthy adults.

A Study to Assess the Safety, Reactogenicity, and Immunogenicity of SK Japanese Encephalitis Messenger Ribonucleic Acid (mRNA) Vaccines (GBP560) in Healthy Adults