Studies on the Immunization of Horses by Habu Snake Venom Treated by Freund's Adjuvant or Dihydrothioctic Acid

It was elucidated that 5mg. or 100mg. of Habu Snake Venom (Trimeresurus flavoviridis) were available as first immunizing doses in horses when it was treated by Freund's incomplete adjuvant or 100mg. of Dihydrothioctic acid. Four weeks after, 1mg. of plain venom was injected subcutaveously into horses, and the dose was then increased duplicatedly in every week. After ten or fifteen times of booster injection, 0.1ml. of the sera showed to neutralize sufficiently the lethal effect and local lesion due to the venom of 300γ or more. The sera were mixed in vitro with the various amounts of venom and injected intramuscularly into the legs of mice. Thus the total amount of venom used for the immunization and the periods of immunization were reduced to one half in compared with the immunization method without adjuvant adopted until now.