Establishment of a VSV-Based Pseudovirus Platform for In Vitro and In Vivo Evaluation of Nipah Vaccine-Induced Neutralizing Responses.

The Nipah virus (NiV) is a zoonotic pathogen characterized by high fatality rates and pandemic potential, whereby there is an urgent need for developing safe and effective vaccines. However, the evaluation of NiV vaccine-induced immunity is hindered by the requirement of Biosafety Level-4 (BSL-4) containment. In this study, we developed a recombinant vesicular stomatitis virus (rVSV)-based pseudovirus-expressing NiV fusion (F) and attachment (G) glycoproteins using a luciferase reporter gene for bioluminescence detection. This pseudovirus was optimized for production in BHK-21 (WI-2) cells, and simultaneous incorporation of NiV-F and NiV-G onto the surface of the pseudotyped virus was confirmed via immunoprecipitation and Western blotting. We evaluated our pseudovirus-based neutralization assay using NiV-F-immunized mouse sera and a commercial anti-NiV-G antibody, confirming robust neutralization by the latter. To establish a BSL-2-compatible model for evaluating in vivo protective efficacy, we performed in vivo imaging, which revealed a marked reduction in the luminescence signal in NiV-G-immunized mice compared to naïve controls, indicating vaccine-induced protection. Our study established an integrated in vitro and in vivo pseudovirus platform using rVSV that enables safe, quantitative, and BSL-2-compatible evaluation of NiV vaccine candidates. This model offers a valuable tool for preclinical screening of vaccine-induced neutralizing antibody responses and protective efficacy.