PROCESS FOR PREPARING ACTIVE TOXOPLASMA GINDII BRADYZOIT VACCINE IN TISSUE CULTURES

摘要

Disclosed herein is a tissue culture produced vaccine for protection of cats against T. gondii, containing an effective amount of bradyzoites and characterized in that the vaccine is substantially free of tachyzoites. The vaccine can be produced on a commercial scale by growing a mutant of T. gondii in a tissue culture to produce bradyzoites by adding T. gondii positive antisera and proteolytic enzymes to inhibit growth or kill residual tachyzoites.