Vaccination with Virus-like Particles Protects Horses From Experimental Bpv-1 Infection

Aims: Bovine papillomavirus types 1 and 2 (BPV-1/-2) are chiefly involved in the pathogenesis of equine sarcoids. We have previously demonstrated that intramuscular immunisation of horses with BPV-1 L1 virus-like particles (VLPs) is safe and highly immunogenic, that BPV-1 and -2 are closely related serotypes, and that intradermal inoculation of horses with cow wart-derived BPV- 1 virions reliably results in the development of transient pseudo- sarcoids. Based on these data, we next performed a virus challenge study. 

Methods: Fourteen horses were immunised with 100 μg of BPV-1 L1 VLP in adjuvant on Days 1 and 28; 7 horses served as nonvaccinated controls. On Day 42, all 21 horses were intradermally inoculated on their neck with 5 x 107 BPV-1 virions per wheal (10 wheals per horse). The horses were monitored for adverse reactions and pseudo-sarcoid formation. Antibody titres were determined for Days 0 and 42. [...]