title: Safety and immunogenicity of BPV-1 L1 virus-like particles in a dose-escalation vaccination trial in horses.
abstract: BACKGROUND
  Infection with bovine papillomaviruses types 1 and 2 (BPV-1, BPV-2) can lead to the development of therapy-resistant skin tumours termed sarcoids and possibly other skin diseases in equids. Although sarcoids seriously compromise the welfare of affected animals and cause considerable economic losses, no prophylactic vaccine is available to prevent this common disease. In several animal species and man, immunisation with papillomavirus-like particles (VLP) has been shown to protect efficiently from papillomaviral infection.
  
  
  OBJECTIVE
  BPV-1 L1 VLPs may constitute a safe and highly immunogenic vaccine candidate for protection of horses against BPV-1/-2-induced disease.
  
  
  METHODS
  Three groups of 4 horses each received 50, 100 or 150 µg of BPV-1 L1 VLPs, respectively, on Days 0, 28 and 168. Three control horses received adjuvant only. Horses were monitored on a daily basis for one week after each immunisation and then in 2 week intervals. Sera were collected immediately before, 2 weeks after each vaccination and one and 2 years after the final boost and analysed by pseudovirion neutralisation assay.
  
  
  RESULTS
  None of the horses showed adverse reactions upon vaccination apart from mild and transient swelling in 2 individuals. Irrespective of the VLP dose, all VLP-immunised horses had developed a BPV-1-neutralising antibody titre of ≥ 1600 plaque forming units (pfu)/ml 2 weeks after the third vaccination. Eight of 10 trial horses still available for follow-up had neutralising antibody titres ≥ 1600 pfu/ml one year and ≥ 800 pfu/ml 2 years after the last immunisation.
  
  
  CONCLUSIONS
  Intramuscular BPV-1 L1 VLP vaccination in horses is safe and results in a long-lasting antibody response against BPV-1. Neutralisation titres were induced at levels that correlate with protection in experimental animals and man.
  
  
  CONCLUSIONS
  BPV-1 L1 VLPs constitute a promising vaccine candidate for prevention of BPV-1/-2-induced disease in equids.
authors: Large Animal Surgery and Orthopaedics, Equine Clinic, University of Veterinary Medicine, Vienna, Austria.
authors: E K
authors: EK
authors: Hainisch
authors: S
authors: S
authors: Brandt
authors: S
authors: S
authors: Shafti-Keramat
authors: R
authors: R
authors: Van den Hoven
authors: R
authors: R
authors: Kirnbauer
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000097:blood; D000914:Antibodies, Viral / Q000097:blood; D052688:Bovine papillomavirus 1 / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D006734:Horse Diseases / Q000517:prevention & control*; D006736:Horses; D014765:Viral Vaccines / Q000009:adverse effects / Q000276:immunology*
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D014765:Viral Vaccines