title: Vaccine Potential of Two Previously Uncharacterized African Swine Fever Virus Isolates from Southern Africa and Heterologous Cross Protection of an Avirulent European Isolate.
abstract: African swine fever (ASF) is a mostly fatal viral infection of domestic pigs for which there is no vaccine available. The disease is endemic to most of sub-Saharan Africa, causes severe losses and threatens food security in large parts of the continent. Naturally occurring attenuated ASF viruses have been tested as vaccine candidates, but protection was variable depending on the challenge virus. In this study, the virulence of two African isolates, one from a tick vector and the other from an indigenous pig, was determined in domestic pigs to identify a potential vaccine strain for southern Africa. Neither isolate was suitable as the tick isolate was moderately virulent and the indigenous pig virus was highly virulent. The latter was subsequently used as heterologous challenge in pigs first vaccinated with a naturally attenuated isolate previously isolated in Portugal. Although a statistically significant reduction in death rate and virus load was observed compared with unvaccinated pigs post-challenge, all pigs succumbed to infection and died.
authors: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort, South Africa.|Department of Tropical Veterinary Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors: R
authors: R
authors: Souto
authors: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort, South Africa.
authors: P
authors: P
authors: Mutowembwa
authors: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort, South Africa.
authors: J
authors: J
authors: van Heerden
authors: Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors: G T
authors: GT
authors: Fosgate
authors: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort, South Africa.
authors: L
authors: L
authors: Heath
authors: Transboundary Animal Diseases Programme, Onderstepoort Veterinary Institute, Agricultural Research Council, Onderstepoort, South Africa.|Department of Tropical Veterinary Diseases, Faculty of Veterinary Science, University of Pretoria, Onderstepoort, South Africa.
authors: W
authors: W
authors: Vosloo
mesh_terms: D017954:Africa South of the Sahara / Q000453:epidemiology; D000357:African Swine Fever / Q000453:epidemiology* / Q000517:prevention & control / Q000821:virology; D000358:African Swine Fever Virus / Q000276:immunology / Q000302:isolation & purification* / Q000472:pathogenicity; D000818:Animals; D056738:Cross Protection; D013552:Swine; D014765:Viral Vaccines / Q000276:immunology*
chemical_list: D014765:Viral Vaccines
keywords: African isolates; African swine fever; challenge; pathology; vaccination; virulence