Table 4.

In vitro live attenuated parasite lines used in vaccines against Babesia.

Vaccine component	Efficacy	Reference
Infected erythrocytes of B. ovis/Akçaova stabilate (passage 5 in in vitro culture) was used for sheep immunization, either alone or mixed with B. ovis rBoAMA-1 protein.	Sheep co-immunized with sublethal dose of B. ovis/Akçaova stabilate and B. ovis rBoAMA-1 protein did not show clinical signs and/or changes in hematological parameters following challenge with B. ovis parasites.	(20)
A B. bovis isolate was cloned by in vitro cultivation and compared to the original cultured isolate for pathogenicity by yearling heifers inoculation. Four of them were inoculated with cloned material and the other 4 with the original culture.	The four animals receiving the cloned parasite showed comparatively minor hematologic changes and no clinical signs. One animal died in the group vaccinated with the original culture. All the animals receiving the cloned parasites were totally immune with no significant change in temperature or decrease in PCV upon challenge 100 days after vaccination.	(172)
Attenuated B. bovis strain by in vitro culturing using equine and bovine serum	All four splenectomized vaccinated calves recovered from mild clinical disease signs, and developed solid immunity upon challenge with virulent strain.	(173)
Possible cross-protection conferred by strains of B. bigemina or B. bovis derived from in vitro culture was tested in cattle by vaccination of calves using individual (B. bovis or B. bigemina) or combined (B. bovis and B. bigemina) live parasites.	The resulted protection was 25, 50, and 100% for cattle immunized with B. bigemina, B. bovis, and B. bigemina/B. bovis, respectively upon natural challenge via Boophilus microplus tick in the field. The mixed vaccinated animals were challenged under control conditions with virulent strains of both protozoan species. All vaccinated animals survived and showed a slight decrease in PCV with unchanged rectal temperature.	(174)
In vitro culture derived Babesia bovis and B. bigemina vaccine to susceptible Bos taurus bulls in a babesiosis endemic area was evaluated. Animals were over 18 months of age	After vaccination for 21 days, all animals under the study were released to a tick infested paddock where they remained until the end of the study. Results showed that a combined B. bovis and B. bigemina vaccine can confer a 70% protection to bovines introduced to Babesia infected areas.	(175)
Co-immunization of cattle with a vaccine against babesiosis (B. bovis and B. bigemina) and Lactobacillus casei	Results suggested that the vaccine efficiency was in part improved due to the L. casei boost of IgG1 over IgG2 antibodies agaisnt B. bovis and B. bigemina.	(176)
Vaccine with Babesia bovis and B. bigemina cultured in vitro maintained in a bovine. Serum and serum-free medium	The vaccine derived from in vitro culture in bovine serum-free medium reached 100% protection vs 83.3% protection with a vaccine derived from in vitro culture in bovine serum medium.	(177)
Long-term (LTCP) cultured B. bovis parasites [Attenuated S74-T3Bo-12 years]	Cattle immunized by this strain showed mild clinical signs, and the parasite wasn’t transmissible in a tick transmission experiment (TBV).	(6)
	The immunized 6 months old calves survived superinfection with Vir-S74-T3Bo without displaying signs of acute babesiosis.	(7)
	In a separate experiment, immunized adult (>1.5 year of age) cattle displayed self-limiting signs of acute infection and protected against challenge with the homologous virulent B. bovis strain Vir-S74-T3Bo.	(8)
Culture-derived attenuated live vaccine against B. bigemina	A single shot of attenuated vaccine was capable of complete protection and parasitic clearance after the challenge with a lethal intravenous challenge virulent calf-derived B. bigemina	(178)
B. gibsoni attenuated Oita isolate 400 in vitro culture passages	Vaccinated dogs with the attenuated strain were protected against the challenge with B. gibsoni virulent Oita isolate	(179)