Efficacy of frozen and refrigerated vaccines against bovine tick fever

Abstract

Babesiosis and anaplasmosis, are endemic in Uruguay and produce economic losses of approximately 14 million dollars per year. To prevent these diseases, refrigerated or frozen vaccines are commercially available. Despite the availability of vaccines, vaccination coverage is very low probably due to several causes: the lack of information of farmers and veterinarians; difficulties in the management and  conservation of the vaccines; and costs per dose and application. In order to compare the efficacy of the refrigerated vaccine with a frozen vaccine against Babesia bovis, Babesia bigemina and Anaplasma marginale we conducted a trial in a commercial farm located in the department of Tacuarembó. Fifty-seven Brangus calves were vaccinated with the refrigerated vaccine and 58 with the frozen vaccine. The indirect immunofluorescence tests for Babesia bovis and Babesia bigemina and the card test for Anaplasma spp. were performed to determine the efficacy of both vaccines at day 62 post vaccination. There were no significant differences between the protection offered by both vaccines (p> 0.05), being between 93% and 98.3% of the animals positive for each of the three agents. These results show that both vaccines are efficient for the prophylaxis of the disease and should be used for the protection of bovines in areas of enzootic instability. It is necessary to continue with the extension tasks to increase the national coverage of vaccinated animals and to investigate possible vaccine failure.