Veterinary Parasitology, 13 (1983) 115-119 115 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands NON-SPECIFIC IMMUNIZATION AGAINST BOVINE TROPICAL THEILERIOSIS (THEILERIA ANNULATA) USING KILLED COR YNEBA CTERIUM PAR VUM R. MANICKAM, S. DHAR and R.P. SINGH* Department of Veterinary Medicine, Haryana Agricultural University, Hissar-125004 (India) (Accepted for publication 25 January 1983) ABSTRACT Manickam, R., Dhar, S. and Singh, R.P., 1983. Non-specific immunization against bovine tropical theileriosis (Theileria annuiata) using killed Corynebacterium parvum. Vet. Parasitol., 13: 115--119. Killed Corynebacterium parvum was used as an adjuvant for the production of non- specific resistance against Thederia annulata in cattle. Groups of cross-bred (Bos indicus × Bos taurus) calves were administered C. parvum adjuvant subcutaneously and were then challenged with T. annulata-infected ticks on 45, 60 or 90 days later. The challenge caused mild reactions in the protected calves. None of the 10 immunized calves died due to theileriosis, whereas all three pairs of susceptible control calves died due to theileriosis. It appears from this pilot study that cattle can be protected non-specifically with C. parvum adjuvant against T. annulata. INTRODUCTION Corynebacterium parvum, a potent immunopotentiator, has been used as an adjuvant either alone or with live or killed vaccines of Plasmodium spp. and Babesia spp. (Clark et al., 1977), Toxoplasma gondii (Swartzberg et al., 1975) and Trypanosoma cruzi (Bomford and McHardy, 1979) to enhance resistance of animals against these parasites. This paper reports an attempt to use C. parvum to produce non-specific resistance against Theileria annulata infection in cattle. MATERIALS AND METHODS Experimental animals Sixteen 8--12-week-old male calves of mixed breed (Bos indicus X Bos taurus) were used. The calves were procured from a farm where strict acari- *Author to whom correspondence should be addressed. 0304-4017/83/$03.00 © 1983 Elsevier Science Publishers B.V.