RNAi therapeutics targeting Japanese encephalitis virus: Gene targets, delivery platforms, and translational barriers

Japanese encephalitis virus (JEV), a neurotropic flavivirus, is a leading cause of viral encephalitis in Asia, particularly affecting children and causing significant morbidity and mortality. Despite the availability of vaccines and vector control strategies, their limited efficacy against emerging genotypes and incomplete coverage necessitate alternative antiviral approaches. RNA interference (RNAi) has emerged as a promising therapeutic modality by exploiting post-transcriptional gene silencing to inhibit viral replication. Notably, conserved viral genes—such as capsid (C), envelope (E), NS3, and NS5—represent optimal RNAi targets across JEV genotypes due to their essential roles in the viral life cycle and minimal sequence variability. Recent advances in delivery platforms, including lipid nanoparticles, lentiviral vectors, and artificial microRNAs, have significantly improved RNAi stability, blood-brain barrier (BBB) penetration, and cell-specific targeting. Comparative insights from related flaviviruses such as Dengue and Zika have further informed effective RNAi design. Preclinical studies have demonstrated potent antiviral effects, with >90 % suppression of viral RNA, substantial reductions in brain viral load, and enhanced survival in murine models. However, clinical translation remains challenged by delivery efficiency, immune activation, off-target effects, and the potential for viral escape mutations. This review summarizes the current landscape of RNAi-based therapeutics for JEV, emphasizing conserved gene targets, delivery innovations, and translational hurdles, and outlines future directions for integrating RNAi into next-generation antiviral strategies.