Immunization with liposome-encapsulated Bothrops jararaca venom.

The venom of Bothrops jararaca (BjV) snake was encapsulated into liposomes. The toxicity and ability of the resultant liposomes to protect mice were evaluated. No acute toxicity was found in mice, when liposomes were subcutaneously injected whereas the same dose of venom emulsified in Freund's adjuvant caused the mice to die. Immunization with the venom containing liposomes and associated immunostimulants, protected 50% of mice after challenge with BjV (4 x LD50). The hemorrhagic activity induced by BjV was reduced after immunization with liposomes associated with immunostimulants, similarly to immunization with BjV emulsified in Freund's adjuvant. However, mice immunized with BjV:Freund's were better protected against the lethal effects of the venom.