Experimental squalene adjuvant. I. Preparation and testing of its effectiveness

The authors prepared experimental lipoid adjuvant of the oil-in-water (O/W) type, based on squalene (ESA: experimental squalene adjuvant), intended for liquid inactivated veterinary vaccines. The final concentration of squalene in the vaccine was 5% (w/v). Detergents Poloxamer 105 in the concentration of 4% (w/v) and Abil-Care in the concentration of 2% were used as emulsifiers. The water component was inactivated virus suspension. Emulsification at decreased temperatures (up to 37 degrees C) fails to denaturate the immunization antigen. The effectiveness of experimental squalene adjuvant was tested using a liquid inactivated adjuvant rabies vaccine and a liquid porcine parvovirus vaccine in comparison with adjuvant-free vaccines or vaccines potentiated with aluminium hydroxide. The squalene adjuvant increased the immunogenic activity of non-potentiated rabies vaccine approximately 1.8-fold, while aluminium hydroxide increased the effectiveness of rabies vaccine only 1.08-fold. The antigenic activity, i.e. the level of specific antibodies after vaccination was significantly increased by using both adjuvants; ESA was more efficient than aluminium hydroxide.