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The experiment applied on four groups of calves, each of four calves. Three calves from each group were vaccinated with one of the following attenuated vaccines: Lumpy skin disease vaccine (LSD), Romanian sheep pox (RSP) vaccine, Held goat pox (HGP) vaccine and dual (bivalent) vaccine of SPV and GPV. All vaccines were evaluated by estimating the cellular immunity using lymphocyte blastogenesis measured by XTT assay, and humeral immunity using serum neutralization and ELISA tests of vaccinated calves. The NI coincided with the ELISA antibody results and corroborated the results of cell mediated immunity which demonstrated the capacity of LSD and dual vaccines to induce immune response higher than SP vaccine and GP vaccines. In conclusion, the current study proved that the LSD and dual vaccines were highly immunogenic than the RSP and HGP vaccines, and dual vaccine could be safely used for vaccination of cattle against lumpy skin disease.

Pigeon pox disease is caused by pigeon pox virus (PPV) that classified within Family Poxviridae, subfamily Chordopoxvirinae, genus Avipoxvirus (APV) which has the largest and the most divergent genome among the chordopoxvirus genera with many species like PPV, Fowl pox virus (FPV) and Turkey pox virus (TPV) (Andraw, 2012). Pigeon pox is a slowly spreading disease characterized by the development of discrete proliferative nodular skin lesions (cutaneous form) characterized by nodular lesions on feather free areas of skin such as legs, peak and eyelids with low mortality and/or fibrino-necrotic lesions on the mucous membrane of the upper respiratory tract (diphtheritic form) with high mortality. In both forms, gross lesions consist of small vesicles that progress further to nodules and finally scab formation Khan et al. (2009) and Hemanth et al. (2014). The conventional laboratory diagnosis of FPV is carried out by electron microscope, virus isolation on chorioallantoic membrane (CAM) of embryonated chicken eggs (ECE) and serologic methods as Virus Neutralization test (VNT) on ECE (Islam et al., 2008). PPV has a double stranded DNA genome which contains a central coding region surrounded by two identical inverted terminal repeat regions. The genome size is 288 kbp approximately and encodes 260 open reading frames Weli et al. (2011). The 4b core protein gene (P4b) of APV encoding a protein with a molecular weight of 75.2 kDa, is usually chosen for comparative genetic analysis. On the other hand, amplification of the AP-p4b by PCR has often been used as a molecular tool for the detection of avian poxviruses (Manarolla et al., 2010). Based on the phylogenetic analysis of (P4b), APV are divided into three clades; clade A (FPV), clade B (Canary Pox virus), and clade C (Psittacine pox virus) (Offerman et al., 2014).

The effect of diethyl aminoethyl (DEAE) dextran on the infectivity titre of sheep pox virus (SPV) was studied with different concentrations (25, 50, 75, 100 µg/ml) of DEAE-dextran on Vero cell culture. It was found that 25 and 50µg/ml were not toxic. The same concentrations were used with sheep pox virus inoculum showing that the best virus titre (10 6.3 TCID 50 /ml) reached with the use of 25µg/ml DEAE-dextran after 10 passages. The enhanced viral fluid was tested in-vivo, by vaccination of susceptible lambs and challenge of them with the virulent sheep pox virus. These lambs showed complete protection against the disease. The SP neutralizing antibody indices (NI) were estimated in the collected serum samples post vaccination and challenge; confirmed that 25µg of DEAE-dextran/ml virus-inoculum induced an increase in neutralizing antibodies in comparison with those induced by currently used sheep pox vaccine.

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