FIELD: biotechnology, molecular biology, veterinary science. SUBSTANCE: invention relates to DNA fragment encoding an immunogenic surface polypeptide of merosoites Eimeria tenella (molecular mass is 33 kDa). During expression of this fragment in microorganism cells the indicated immunogenic polypeptide is formed. DNA fragment encoding polypeptide is introduced into suitable vector, microorganism cells are transformed with this vector and the end recombinant DNA is isolated from cells where polypeptide expression is occurred. The end polypeptide is isolated from cultural medium. DNA fragment encoding this polypeptide is cloned in a suitable vector, introduced into plasmid containing TK gene of vaccine virus for recombination. Cultured cells are transformed with obtained recombination plasmid temperature-sensitive vaccine virus and vaccine virus of wild type. Transformed cells are cultured at increased temperature, TK-negative vaccine virus is isolated, used its for infection of cultured cells and the end recombinant vaccine virus is selected by the presence of gene of merosoites. Vaccine has recombinant vaccine virus containing DNA fragment or immunogenic surface polypeptide of merosoites and physiologically acceptable carrier. Invention ensures to obtain important vaccine antigens that are essential in protection of domestic poultry and other live organisms against coccidiosis. EFFECT: improved method of preparing polypeptide, plasmid DNA, vaccine virus, microorganism and vaccine. 10 cl, 1 tbl, 15 dwg, 3 ex
