The characteristics of calcium phosphate gel were investigated to use it for adjuvant of animal infectious diseases vaccine in Pyongyang agricultural college of
Now, there are several kinds of adjuvant including oil emulsion, aluminum gel, propolis, chrome potassium alum. Among them, oil emulsion is widely used, and aluminum gel is also used as adjuvant of approved vaccines. Aluminum gel enhances the immunity effectively, but causes serious inflammation on the inoculation site, which the duration is long.
Calcium phosphate gel was introduced to overcome the negative effect of aluminum gel.
Typical calcium phosphate gel available as adjuvant was made when 0.1mol/L CaCl2 was mixed with 0.1mol/L Na2 HPO4. 0.1M calcium phosphate gel had absorbability for the tested E. coli strain and viruses including NDV and RHDV and the dissociation of the antigens didn't occur for 180 days in 0~30℃ after antigen absorption.
After the vaccines were injected to mice, marmots and rabbits, there was no any clinical sign by the gel and difference in hematological indices compared to before the injection of the vaccines. And there was also no difference in hematological indices in the case of pigs, chickens and ducks compared to before the injection of the vaccines.
When aluminum hydroxide gel was injected to the muscles of 10 days-chicken and ducks, the local inflammation was disappeared after 60 days of the injection and it was done after 30 days in calcium phosphate gel. When calcium phosphate gel as adjuvant of duck coli bacillus disease vaccine was applied to fattening duck, the antibody titer, which was similar to aluminum hydroxide gel contained vaccines was twice times higher than the control (vaccine without any adjuvant), and the titer duration of the antibody was longer than the control.
The virulent strain defense effect for duck coli bacillus disease vaccine with calcium phosphate gel as adjuvant was similar to that for vaccine with aluminum hydroxide gel after 30 days of the injection, and was 100% and 70% in vaccines with and without calcium phosphate gel, respectively. When the calcium phosphate gel was used as adjuvant of RHDV vaccine, the antibody titer was higher than the control and the duration was longer.
The results showed the calcium phosphate gel was very useful as adjuvant of animal infectious disease vaccine.
