RESEARCH UPDATES ON MALIGNANT CATARRHAL FEVER Cristina W Cunha, - - PowerPoint PPT Presentation
RESEARCH UPDATES ON MALIGNANT CATARRHAL FEVER Cristina W Cunha, DVM, PhD Veterinary Medical Officer Animal Disease Research Unit ARS USDA - Pullman WA Malignant Catarrhal Fever (MCF) MCF-virus group Ovine herpesvirus 2 (OvHV-2)
Cristina W Cunha, DVM, PhD Veterinary Medical Officer Animal Disease Research Unit ARS – USDA - Pullman WA
OvHV-2
➢ Ovine herpesvirus 2 (OvHV-2)
clinically susceptible hosts
➢ Ovine herpesvirus 2 (OvHV-2)
clinically susceptible hosts
OvHV-2 reservoir OvHV-2 clinically susceptible hosts MCF
neg = OvHV-2 uninfected pos = OvHV-2 infected MCF = disease
102 103 104 105 106 107 108 109 Sheep neg pos pos pos pos pos pos MCF Cattle neg pos pos MCF Pigs neg pos MCF Rabbits neg pos MCF MCF Bison neg Pos MCF MCF OvHV-2 inoculum (genome copy number)
Li et al., 2005; Taus et al., 2005; Taus et al., 2006; O’Toole et al., 2007; Gailbreath et al., 2009; Li et al., 2012
➢ Separation of clinically susceptible
➢ Production of virus-free carriers
0.4 % 6.1 % 17.5 5 %
Li et al., 2008
➢ Stimulate a neutralizing antibody response capable of blocking
Technology Transfer
Regulatory documentation Scale-up production Distribution
Vaccine System Development
Expression system selection and evaluation Delivery (route, dose, etc.) Animal challenge experiments
Target Selection
Viral proteins capable of inducing a protective response In vitro assessment
➢ Antibodies anti-OvHV-2 gB, gH and gL
can block the virus and prevent MCF ➢ There is no culture system to grow OvHV-2
gB gH/gL
Li et al. , 2013; Cunha et al., 2015; Cunha et al., 2016; Cunha et al., 2017
OvHV-2 lethal dose Anti-gB, gH, gL antibodies Genetic immunization Infection
MCF Sub clinical infection
Virus neutralization
No infection
➢ Development of a recombinant BoHV-4
expressing the OvHV-2 vaccine targets
AlHV-1 AlHV-2 AlHV-2-like CpHV-2 Ibex-MCFV
OvHV-2-like (big horn sheep) OvHV-2 (domestic sheep)
CpHV-3
Washington State University, Pullman WA Animal Disease Research Facility, Pullman WA Palouse Region, Washington
OvHV-2 probe Arteritis in sheep
Health Status Group OvHV-2 genome copies Intestine Lung Kidney Liver Total MCF Lamb 457,000 433,000 283,000 51,500 306,000 Clinically Normal Cohort lambs 3,870 4,050 330 730 2,240 Lambs 570 210 10 40 210 Adults 430 30 20 35 130
Phillips et al. , 2018 Pesavento et al. , in preparation