IMMUNITY IN CATTLE TO BABESIA-BOVIS AFTER SINGLE INFECTIONS WITH PARASITES OF VARIOUS ORIGIN

Sixty calves, 3 to 6 months old, were vaccinated once against Babesia bovis in groups of 10, by the following methods: (a) tick infestation; (b) inoculation of virulent parasites obtained from the tick‐infested animals immediately after infection; (c) inoculation of the parasites used in (b) attenuated by passage through splenectomised calves; (d) inoculation of commercially‐available, living, attenuated vaccine; (e) inoculation of virulent parasites obtained from the tick‐infested animals in (a) one year after infection; (f) inoculation of the parasites used in (e) attenuated by passage. All vaccinated animals were maintained tick‐free and were strongly immune to challenge with a heterologous strain of B. bovis approximately 4 years after vaccination. There was no difference in immunogenicity between any of the B. bovis populations. Copyright © 1979, Wiley Blackwell. All rights reserved