A modified vaccinia Ankara virus (MVA) vaccine expressing African horse sickness virus (AHSV) VP2 protects against AHSV challenge in an IFNAR -/- mouse model.
Authors: Castillo-Olivares Javier, Calvo-Pinilla Eva, Casanova Isabel, Bachanek-Bankowska Katarzyna, Chiam Rachael, Maan Sushila, Nieto Jose Maria, Ortego Javier, Mertens Peter Paul Clement
Journal: PloS one
Summary
African horse sickness remains a significant biosecurity concern for non-endemic regions, where live attenuated vaccines—the current standard in endemic areas—pose unacceptable risks; this research evaluated a recombinant MVA-based vaccine expressing the AHSV VP2 capsid protein as a safer alternative. Using an IFNAR-deficient mouse model, the authors characterised AHSV pathogenesis and subsequently assessed whether immunisation with MVA-VP2 could provide protection against viral challenge. The recombinant vaccine successfully induced protective immunity, as vaccinated mice showed significantly reduced viral loads and improved survival compared to controls following challenge. This work demonstrates that a rationally designed, non-live vector vaccine can stimulate effective immune responses against AHSV structural antigens, whilst also validating the mouse model as a practical alternative to expensive, ethically challenging equine studies for preliminary vaccine development and immunological investigation. For practitioners in countries with strict AHS regulations, these findings suggest a viable pathway towards safer vaccine candidates that could eventually offer protection without the biosecurity constraints of attenuated live vaccines, though further development and large animal trials remain essential before clinical application.
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Practical Takeaways
- •This pre-clinical research supports development of safer recombinant vaccines for AHS that could be used in non-endemic countries without biosecurity risks of live attenuated vaccines
- •Mouse model validation enables faster, more ethical vaccine testing before equine trials, potentially reducing use of infected horses in high-containment facilities
- •MVA-VP2 vaccine approach represents a promising middle ground between safety concerns of live vaccines and practical/financial constraints of equine-based research
Key Findings
- •Modified vaccinia Ankara (MVA) vaccine expressing AHSV VP2 provided protective efficacy against AHSV challenge in IFNAR-/- mouse model
- •Experimental mouse model was successfully characterized for AHSV infection and vaccine immunology research
- •Recombinant viral vector approach using MVA demonstrates potential as alternative to live attenuated vaccines for AHS control