Characterization of sheep pox virus vaccine for cattle against lumpy skin disease virus

Abstract

Lumpy skin disease is of significant economic impact for the cattle industry in Africa. The disease is currently spreading aggressively in the Near East, posing a threat of incursion to Europe and Asia. Due to cross-protection within the Capripoxvirus genus, sheep pox virus (SPPV) vaccines have been widely used for cattle against lumpy skin disease virus (LSDV). In the Middle East and the Horn of Africa these vaccines have been associated with incomplete protection and adverse reactions in cattle post-vaccination. The present study confirms that the real identity of the commonly used Kenyan sheep and goat pox vaccine virus (KSGP) O-240 is not SPPV but is actually LSDV. The low level attenuation of this virus is likely to be not sufficient for safe use in cattle, causing clinical disease in vaccinated animals. In addition, Isiolo and Kedong goat pox strains, capable of infecting sheep, goats and cattle are identified for potential use as broad-spectrum vaccine candidates against all capripox diseases.

Keywords: Kenyan sheep and goat pox virus; Lumpy skin disease; Vaccine.

Fig. 1

Differences in the melting point temperatures for the virulent and attenuated capripoxvirus strains obtained after fluorescence melting curve analysis, using species-specific PCR method (Lamien et al., 2011b).

Fig. 2

Molecular phylogenetic analysis of (a) the capripoxvirus RNA polymerase subunit (RPO30) gene and (b) the capripoxvirus G-protein-coupled chemokine receptor (GPCR) gene. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) are shown next to the branches. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances are in the units of the number of base substitutions per site. The sequences determined in this study are marked with a black diamond.

Fig. 2

Molecular phylogenetic analysis of (a) the capripoxvirus RNA polymerase subunit (RPO30) gene and (b) the capripoxvirus G-protein-coupled chemokine receptor (GPCR) gene. The percentage of replicate trees in which the associated taxa clustered together in the bootstrap test (1000 replicates) are shown next to the branches. The tree is drawn to scale, with branch lengths in the same units as those of the evolutionary distances used to infer the phylogenetic tree. The evolutionary distances are in the units of the number of base substitutions per site. The sequences determined in this study are marked with a black diamond.