Evaluation of oral and injectable liposome-based vaccines with synthesized lipid for Japanese encephalitis virus in Sprague-Dawley rats.

Abstract

Purpose: Japanese Encephalitis Virus (JEV) is a mosquito-borne flavivirus that causes severe neurological complications and high mortality rates in Asia. Developing vaccines is crucial for controlling its spread. Liposomes, as advanced drug delivery systems, have demonstrated promise in reducing systemic toxicity and enhancing drug penetration across the blood-brain barrier. Given these advantages, this study aimed to evaluate the immunoglobulin G (IgG) antibody response to JEV antigen administered via injection and liposome-based oral delivery.

Materials and methods: The liposome-based vaccine used in this study was formulated from a custom-synthesized lipid to enhance the vaccine's efficacy. The rats were divided into 3 groups: a control group, a liposome-based injectable vaccine group, and a liposome-based oral vaccine group. Blood samples were collected at 3 and 5 weeks post-administration to measure IgG antibody levels.

Results: As expected, the control group exhibited no immune response. In contrast, liposome-based oral and injectable vaccine groups showed considerable results. The liposome-based injectable vaccine group demonstrated a strong increase in IgG levels, and the liposome-based oral vaccine group exhibited a moderate but notable rise. At 5 weeks, antibody levels in the control group returned to baseline, whereas the vaccinated groups maintained elevated levels.

Conclusion: The injectable formulation induced a stronger immune response; however, the oral formulation showed potential as an alternative. These findings suggest that refinement of the oral formulation may provide practical advantages such as ease of administration, non-invasiveness, and improved logistics. Such features could potentially contribute to broader immunization efforts, including those aimed at global disease control.