Onderzoek naar de epidemiologie en vaccinologie van het Lumpy Skin Disease Virus (LSDV) in Ethiopië: In-silico ontwerp van een multi-epitoopvaccin en de expressie ervan in E. coli

Ethiopia is the one of the richest livestock population in Africa with more than 60 million heads of cattle (UNDP, 2018). Livestock production remains crucial and represents a major asset among resource poor small holder farmers by providing milk, meat, skin, and manure and traction force (CSA, 2016). The contribution of livestock to the national economy particularly with regard to foreign currency earnings is through exploration of live animal, meat and skin and hides (MoARD, 2008). Poor health and productivity of animal due to diseases like that of Lumpy skin disease have considerably become the major problem to the potential of livestock industry in Ethiopia (Mekonnen et al., 2001; Molla, 2018). Lumpy skin disease (LSD) is a viral disease of cattle and buffalo which is caused by a Capripoxvirus of family Poxviridae. It is characterized by skin nodules, pox lesions in ocular, nasal and oral mucous membranes, and in surface of internal organs, skin edema, fever, lymphadenitis and sometimes mortality (Radostitis et al., 2006).The genus Capripoxvirus is comprised of three closely related viruses, i.e. Sheeppox virus (SPPV), Goatpox virus (GTPV) and Lumpy skin disease virus (LSDV). Various strains of Capripoxvirus are responsible for the disease and these are antigenically and serologically indistinguishable among themselves (Kitching, 2003; Babiuk et al., 2008). Although they are antigenically related, genome sequencing has shown that CaPVs are phylogenetically distinct (Le Goff et al., 2009; Lamien et al., 2011). LSD is an endemic disease in Ethiopia having serious consequences on both national and household incomes. It is continuously the problem of almost all the regions and agro ecological zones of country (Molla et al., 2017). LSD outbreak occurred at least once in all of the regional states and city administrations in Ethiopia since its first occurrence in 1981 (Mebratu et al.,1981; Molla , 2018). The LSD economic impact is considerable for livestock industry in affected regions and nations (Tuppurainen et al., 2017). In Ethiopia, the LSD field outbreak economic impact was extensively studied by Molla (2018); in his PHD work, revealed a total economic loss of USD 1176 per affected herd (USD 489 in the subsistence and USD 2735 in the commercial farm type). Even though, animal movement restriction, Vaccination, and slaughter of infected and in-contact animals are major recomendations for LSD control and eradication. However, vaccination is the most manageable and realistic approach to control the disease in endemic and resource poor countries like Ethiopia (Carn, 1993; Tuppurainen et al., 2014). Although, Live attenuated vaccines based on sheep pox virus (for example, Kenyan sheep pox (KS1 O-180), Romanian sheep pox and Yugoslavian RM 65 sheep pox vaccines), goat pox virus (Gorgan goat pox vaccine), and LSDV (Neethling strain vaccine) have been used for the control of LSD in differnt countries (Tuppurainen et al., 2014; Gari et al., 2015), in Ethiopia, only Kenyan Sheep and Goat Pox (KS1 O-180) vaccine produced by National Veterinary Institute (NVI) is currently under use throughout the country(Gari et al., 2015; Molla, 2018). But LSD vaccine failure has been reported in several countries including Ethiopia. During the 2006 outbreak in Israel 11% of RM 65 vaccinated cattle became infected (Brenner et al., 2009). In Jordan LSD morbidity of 4.7% in cattle populations vaccinated with RM 65 reported (Abutarbush, 2014). In Oman an outbreak for more than three months after vaccination with Kenyan sheep and goat pox vaccine have been reported (Kumar, 2011). In Ethiopia, LSD vaccine failure has been reported since 1993 (Carn, 1993). More recently, a study by Molla and Coworkers indicated that KS1 O-180 vaccination has poor efficacy in protecting cattle populations against LSD, neither by direct clinical protection nor by reducing transmission, and suggested the urgent need to either improve the quality of the vaccine or to develop potent alternative vaccines that will confer good protection against LSD (Molla et al., 2017). In order to control and prevent LSD, the Ethiopian government considered LSD one of the top prioritized diseases of cattle in its Growth and Transformation Plan (GTP) 2 because of its major trade embargoes (Ethiopia-Livestock Master Plan Brief, 2015). Among the few of recommended strategies to control and stamp out this disease, vaccination is the major and possible way for a county with huge transhumance and nomadic society which make control of cattle movement very taff. Different studies reports confirmed that, there is lack of detailed information on the local circulating isolates and their relation to the vaccine strain locally used in Ethiopia (Gelaye et al.,2015) as well as commercially available vaccines strains (Neethling lumpy skin disease virus , x10RM65 sheep-pox live and KS1 O-180 attenuated vaccines) used in other LSD endemic regions (countries). Hence, there is a need to develop a new, more efficient vaccine strains by isolating and characterizing the local field LSDV strains (isolates) at genetic level, and in parallel to study the effectiveness of commercial available vaccines stains through which getting effective and potent vaccine against LSD in Ethiopia.<br />2. Objectives General objective Thus, with the above basic gaps and recommendations, the rationale of this study project is aimed to isolating and characterizing the field LSDV strains at genetic level to develop potent alternative vaccine from locally circulation LSD strains and in parallel to study the effectiveness of commercial available vaccines stains that will confer good protection against LSD in Ethiopia that can subsequently be used to develop protective vaccine to control the disease in the country in line with the countries Livestock master plan. Specific objectives WP1: Outbreak investigation, virus Isolation and molecular detection of the LSD field strains WP2 :Molecular characterization and sequence analysis of G-protein-coupled chemokine receptor (GPCR) and the DNA-dependent RNA polymerase subunit (RPO30) gene of Capripoxvirus isolates and vaccine strains WP3: A live LSD vaccine development from local strains through a virus attenuation and genetic engineering techniques.