Vaccination with an in vitro culture attenuated Babesia bovis strain safely protects highly susceptible adult cattle against acute bovine babesiosis.

Evidence from this study indicates that Att-S74-T3Bo safely protects highly susceptible adult cattle against challenge with a homologous virulent strain of . In conclusion, Att-S74-T3Bo may be considered as a potential efficient and sustainable attenuated candidate vaccine strain to control acute bovine babesiosis in highly susceptible adult cattle. Future studies should focus on increasing the number of animals vaccinated, duration of immunity, and efficacy of this attenuated strain against heterologous virulent parasite strains.