Effect of Di-ethyl aminoethyl (DEAE) Dextran on the infectivity titre of sheep pox virus in-vitro and in-vivo

Abstract

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.