Immunisation of calves against East Coast fever without drug treatment

A mild Theileria parva stock (T. parva Lanet, Kenya) was used for vaccination of calves prior to a lethal challenge with a heterologous stock (T. parva Marikebuni, Kenya). Although vaccination did not produce an important parasitaemia in the calves, high levels of antibodies were observed using an immuno-fluorescent assay test. All the vaccinated animals survived the lethal challenge, but none of the control animals. Protection was better when using either an autologous vaccine or a tick stabilate rather than a heterologous vaccine.