An equine herpesvirus type 1 (EHV-1) expressing VP2 and VP5 of serotype 8 bluetongue virus (BTV-8) induces protection in a murine infection model.
Authors: Ma Guanggang, Eschbaumer Michael, Said Abdelrahman, Hoffmann Bernd, Beer Martin, Osterrieder Nikolaus
Journal: PloS one
Summary
# Editorial Summary Bluetongue virus serotype 8 caused devastating losses across European ruminant flocks in 2006–2008, creating urgent demand for effective vaccines that could distinguish vaccinated from naturally infected animals—a critical requirement for disease control programmes and trade. Researchers engineered a recombinant equine herpesvirus type 1 (EHV-1) to express VP2 and VP5 surface proteins from BTV-8, choosing EHV-1 as a novel viral vector because it replicates reliably in vitro without genetic instability. When administered to mice, the dual-antigen vaccine induced BTV-8-specific neutralising antibodies; crucially, mice receiving the VP2–VP5 recombinant virus achieved 100% survival following lethal BTV-8 challenge, whereas those vaccinated with VP2 alone did not, suggesting synergistic protection from the combination. By deliberately omitting VP7 from the vaccine construct, researchers created a practical DIVA marker allowing serological differentiation between vaccinated and naturally infected animals. Although this proof-of-concept employed a murine model rather than natural ruminant hosts, it demonstrates that EHV-1 vectored vaccines merit further development as a strategy for BTV control, particularly in regions where DIVA-compatible vaccination is mandated for trade or disease eradication programmes.
Read the full abstract on PubMed
Practical Takeaways
- •This research demonstrates proof-of-concept for using EHV-1 as a vectored vaccine platform for BTV in a murine model; relevance to equine practice requires further investigation
- •The DIVA-compatible approach could improve disease surveillance by distinguishing vaccinated from naturally infected animals
- •Findings are currently limited to laboratory mouse models and do not yet translate to clinical application in horses or ruminants
Key Findings
- •EHV-1 recombinant viruses stably expressed BTV-8 VP2 and VP5 transgenes with growth kinetics identical to parental virus in vitro
- •Recombinant EHV-1 expressing both VP2 and VP5 elicited BTV-8-specific neutralizing antibody response in immunized mice
- •100% of IFNAR(-/-) mice vaccinated with EHV-1 carrying VP2 and VP5 survived lethal BTV-8 challenge, whereas VP2 alone did not confer protection
- •VP7 successfully functioned as a DIVA marker to differentiate vaccinated from infected animals