Immunogenicity of an Fc-Fused Nipah Virus Attachment Glycoprotein Vaccine Candidate

Nipah virus (NiV) comprises two major genotypes, the Malaysia (NiV-M) and Bangladesh (NiV-B) strains. It is a zoonotic pathogen with high virulence in humans and pigs. The attachment glycoprotein (G) is considered a target for NiV vaccine development. Here, we report an Fc-G fusion protein, generated by fusing the ectodomain of NiV-B G to an immunoglobulin G1 (IgG1) fragment crystallizable (Fc), and evaluated its immunogenicity in three animal species. In mice, Fc-G was evaluated together with an unfused G comparator and induced potent G-specific antibody levels and strong neutralizing activity against NiV pseudovirus. Robust antibody responses were elicited in Fc-G-immunized Syrian hamsters and pigs; high-level neutralizing antibodies against both NiV-M and NiV-B were also detected. Neutralizing antibody titers remained high at 91 days post-immunization in hamsters. These findings demonstrate that Fc-G elicits robust, durable binding and cross-reactive neutralizing antibody responses.