Efficacy of Salmonella Bivalent Vaccine

The work was performed to investigate the efficacy of Salmonella bivalent vaccine containing Salmonella gallinarum and Salmonella pullorum in Shaver brown chicken. Birds were immunized at 7 weeks of age with 0.5ml (4.7 ×107CFU/ml) of the bivalent vaccine followed by administration of a booster dose after 35 days of primary vaccination. At 3 weeks of primary vaccination, mean PHA antibody titre of sera samples were recorded as 104.00±11.71 with S. gallinarum antigen and 112.00±10.47 with S. pullorum antigen. Serum obtained at 5 weeks post primary vaccination (WPV) the mean PHA antibody titres were 96.00±12.09 with S. gallinarum and 80.00±10.47 with S. pullorum antigen. It was observed that the birds having administered with the primary and secondary (booster) schedule of bivalent vaccination and exhibiting at 4 weeks of booster vaccination a mean titres of 104.00±11.71 with both S. gallinarum and S. pullorum antigen withstood the challenge infection by their virulent cultures given IM with 1ml containing 8.6×1013 CFU/ml and 8.9×1013 CFU/ml respectively. It was demonstrated that experimental Salmonella bivalent vaccine conferred protection against challenge infection and found to be safe.