Reactions to heartwater vaccination in crossbred Zebu cattle.

One thousand and ninety-four crossbred Zebu cattle were immunized against heartwater with a sheep-blood vaccine containing the Ball 3 strain of Cowdria ruminantium. Animals experiencing febrile reactions were treated at various stages of the reaction with tetracycline. Four hundred and sixty-two (42.

Efficacy of an Australian Babesia bovis vaccine strain in Malawi.

Three calves vaccinated with the Australian Ka strain of Babesia bovis were fully protected against experimental infection with an isolate from a farm on which four of 210 vaccinated cattle had died from B bovis infection. A degree of cross protection against the isolate was demonstrated in one calf which had been infected previously with Babesia bigemina.

Use of serological response to evaluate heartwater immunization of cattle.

Frozen blood vaccine containing the Ball 3 strain of Cowdria ruminantium is prepared by an FAO/DANIDA Project in Malawi for the immunization of improved dairy cattle against heartwater. The immunogenicity of vaccine batches for cattle has been quantified and different regimens for immunization have been evaluated using indirect immunofluorescence to assess antibody responses. Infected endothelial cells grown in culture are used as antigen.