Results of Pre-Clinical and Clinical Tests of Organic Hydroxyapatite as Adjuvant of Bacterial Vaccine

Vaccination continues to be one of the most effective ways to protect against infectious diseases; therefore, there is a need to develop new vaccines that have low cost and are used either once or for long periods of time.The current study aims to test organic hydroxyapatite in bacterial vaccines on laboratory and farm animals and determine its adjuvant and immunogenic properties. In pre-clinical tests, white mongrel mice weighing 18-20g and rats weighing 250-300g were used. Adjuvant (organic hydroxyapatite) separately and as part of vaccines was administered subcutaneously, intraperitoneally and intramuscularly at a dose of 0.5 ml. Clinical tests of adjuvant were carried out on Holstein-Friesian cows and calves. Experimental vaccines were used: 1) a split-conjugated vaccine against animal brucellosis (as antigens it included the components of brucella (Br. Abortus); 2) a vaccine against mastitis of cows. Results showed that PhA, neutrophils and monocytes in the blood smears of the control group were 1.4 times lower, and twice as much compared to the vaccine without the adjuvant. The maximum PhI(FI) was observed in animals immunized with a split-conjugated vaccine against brucellosis of animals with the adjuvant. The disappearance of vaccine antibody titer in the blood after 30 days was stated, which is positive in the diagnosis of brucellosis. The anti-mastitis vaccine with the adjuvant demonstrates prophylactic properties. In conclusion: Organic hydroxyapatite, obtained from the bones of animals by pyrolysis, displays adjuvant and immunogenic properties when used in bacterial vaccines.