Studied on the Habu Snake (Trimeresurus flavoviridis) Venom Toxoid

Abstract

Mice and rabbits were immunized with Habu Snake Venom treated with equal amount of Freund's incomplete adjuvant, and Cocarboxylase or Dihydrothioctic acid (DHTA). After four weeks, 3 or 5 booster injections of untreated or DHTA treated venom were given weekly. And then, the neutralizing effects of the sera of the animals were tested. They were also challenged intramuscularly into the legs with the venom.
It was elucidated that those immunized animals were protected from local hemorrhagic and necrotic action and lethal effect of venom in considerable degree although the protective potency of the sera of the animals was lower than that of antivenin used for treatment of snake bite in man. As it was also confirmed that no side reaction was seen by the injection of DHTA treated venom, an active immunization of men was tried, injecting 5mg of DHTA treated venom divided into two at the interval of two weeks. The immunizing potency of the sera of vaccinated persons was almost the same as that of the animals. Thus, it was suggested that DHTA inactivated toxoid of habu venom was proved to be useful for prophylaxis against the legion caused by Habu snake bite.