IMMUNE-RESPONSE TO DIFFERENT DOSES OF TISSUE-CULTURE RINDERPEST VACCINE IN SHEEP

The immune response to different doses, viz. 1, 3 and 10 cattle immuni zing doses (CID), of tissue culture rinderpest virus (TCRV - Kabete O) vaccine in month-old lambs were assessed in the presence of insignifi cant level of maternally derived antibodies (MDA). The booster effect to similar doses of vaccine at the age of 6 months was assessed. The p rimary immune response to 3 CID in 6-month-old lambs was also assessed and compared with the response in month-old lambs for the same dose o f vaccine (3 CID). Serum samples collected at various intervals were s ubjected to SNT, ELISA, PHA and SPACE. No significant difference was o bserved in primary and secondary antibody response between groups. A d ose of I CID (1000 TCID) elicited adequate primary SN antibody respons e (log 1.62 +/- 0.1). Lambs at the age of 1 month and 6 months respond ed equally to 3 CID. All the vaccinates withstood the challenge with v irulent rinderpest virus (10(4) sheep ID50) at 18 months of age. ELISA and SPACE were highly agreeable with the results of SNT.