Pulpy kidney disease/tetanus/lamb dysentery vaccine

摘要

A combined purified vaccine for the protection of sheep and lambs against tetanus and pulpy kidney disease comprises an aqueous preparation of toxoided E-toxin from Clostridium welchii, type D, and toxoided tetanus toxin, containing not less than 30 flocculation equivalents (Fl.E) of toxoided 8-toxin, not less than 5 flocculation equivalents of toxoided tetanus toxin, not more than 0.075 milligrams protein nitrogen and not more than 0.75 milligrams total nitrogen per millilitre of the preparation. Protection is also obtained against dysentery by using the above vaccine containing additionally toxoided B- and E-toxins from Cl. welchii, type B, if desired, reinforced with additional toxoided B-toxin from Cl. welchii, type C. This vaccine contains not less than 5, preferably 10, Fl.E. of toxoided tetanus toxin, not less than 30, preferably 60-70, Fl.E. of toxoided E-toxin from Cl. welchii, type D, not less than 30, preferably 70-80, Fl.E. of B-toxin from Cl. welchii, type B, and not less than 20, preferably 30-40, Fl.E. of toxoided B-toxin from Cl. welchii, type C. The purified toxoid is prepared by anaerobically culturing a toxigenic strain of the producing organism, e.g. Cl. welchii, type D in a culture medium such as papin digest of horse meat of pH 8.0 at 37 DEG C. for 18 hours. Separating the bacteria from the medium and converting the toxin and protoxin in the clarified medium to toxoid and protoxoid by treatment with formaldehyde (1% on medium) for 14 to 18 days at 37 DEG C. converting the protoxoid to toxoid by treatment with trypsin for 30 to 90 minutes at 37 DEG C. and precipitating the toxoid from the medium by the addition of ammonium sulphate. The toxoid is dissolved in water and dialysed to remove residual ammonium sulphate. The purified toxoid is adsorbed on to a parenterally acceptable pharmaceutical carrier such as aluminium hydroxide gel or aluminium phosphate gel. The various purified toxins are adsorbed on to separate carriers before mixing in the required proportions to produce the potencies desired. The vaccine may be buffered at pH 7.0 and contain 0.85% sodium chloride and a preservative.