Paramyxovirus-based feline vaccines for FHV1, FCV and FPV

Overview

Feline herpesvirus 1 (FHV1), feline calicivirus (FCV), and feline panleukopenia virus (FPV) are significant pathogens affecting domestic cats, creating urgent demand for safe and efficacious single or combination vaccines. This research proposes developing vaccine candidates using parainfluenza virus 5 (PIV5) and Sendai virus (SeV) as viral vectors to express protective antigens from these three feline pathogens. The resulting recombinant vaccines (PIV5-FHV1, FCV and FPV; SeV-FHV1, FCV and FPV) aim to provide robust immunity against major feline infectious diseases.

Technical specifications

Vector platform advantages:

• PIV5 and SeV exhibit low pathogenicity with a broad host range
• Both vectors grow to high titers in multiple cell types and eggs
• Genomes remain stable even with foreign gene insertions
• Multiple administration routes supported: intranasal, intramuscular, and oral
• Prior exposure to PIV5 does not prevent PIV5-vectored vaccines from generating strong immunity

Research approach:

• Generate recombinant PIV5 and SeV expressing major protective antigens of FHV1, FCV, and FPV
• Analyze recombinant viruses in cultured cells
• Test efficacy in mice using different administration routes (intranasal, oral, intramuscular) and prime-boost immunization schemes (homologous and heterologous)
• Evaluate immune responses by ELISA, IFA, and virus neutralization assays
• Validate efficacy in cats through clinical observation, antibody measurement, and challenge studies

Prior validation:

The research team has successfully generated recombinant PIV5 and SeV expressing antigens of ASFV, PRRSV, and porcine coronavirus, with two-dose inoculation eliciting good immune responses in mice as measured by IFA and neutralization assays.

Technology readiness level

This vaccine platform is at an early-to-mid stage of development. The vector technology (PIV5 and SeV) has been validated through prior work on other animal pathogens, demonstrating proof-of-concept for antigen expression and immune response generation. Current efforts focus on generating feline pathogen-specific constructs and progressing through mouse studies to eventual validation in cats, the target species. The technology readiness level is approximately TRL 3-4, with anticipated progression toward TRL 5-6 following successful cat trials and challenge studies.