A preliminary field trial to evaluate the use of immunisation for the control of naturally acquired Taenia saginata infection in cattle.

The efficiency of immunisation of cattle with antigens collected during 14-day in vitro cultivation of Taenia saginata or T hydatigena oncospheres for the control of naturally acquired bovine cysticercosis was tested on a farm which uses sewage effluent to irrigate pasture. A total of 260 first-calf heifers of mixed breed were divided into four groups which were either sham-vaccinated or vaccinated with T saginata antigen at 49 to 124 days or 16 to 91 days before calving or vaccinated at 49 to 124 days prepartum with T hydatigena antigen. Ten calves from each group were killed at about three months of age and all muscles, including heart, tongue and oesophagus, were examined for cysticerci. Precalving vaccination with T saginata antigen significantly reduced the number of cysticerci found. Calves from sham-vaccinated cows were either sham-vaccinated or vaccinated with T saginata antigen or T hydatigena antigen at 46 to 121 days olds. Calves from cows immunised with T saginata antigen were either sham-vaccinated or immunised with T saginata antigen. Calves from cows injected with T hydatigena antigen were either sham-vaccinated, vaccinated once with T hydatigena antigen when 46 to 121 days of age or vaccinated twice with T hydatigena antigen at median ages of 65 days and 99 days. All these calves were killed at 13 to 14 months old and their heart, diaphragm, tongue and masticatory muscles examined for cysticerci. Of the 38 surviving sham-vaccinated calves from sham-vaccinated cows, 21 animals (55 per cent) were infected. Several of the vaccination regimes reduced this rate of infection significantly but the most effective was precalving vaccination of the cow and vaccination of the calf with T saginata antigen which reduced infection by 78 per cent compared with the controls. Precalving vaccination of cows with T hydatigena antigen together with double vaccination of their calves with the same antigen preparation also significantly reduced infection in the calves by 64 per cent.