NEW MULTIVALENT VACCINE AGAINST HUMAN LEPTOSPIROSIS AND A METHOD FOR ITS PRODUCTION Russian patent published in 2021 - IPC A61K39/00 A61P33/02 

FIELD: medical microbiology.

SUBSTANCE: described polyvalent vaccine against human leptospirosis contains as antigens strains of four leptospira serogroups: Leptospira interrogans Icterohaemorrhagiae copenhageni, Rat 2/466; L. interrogans Grippotyphosa grippotyphosa, Microtus arvalis 30/469; L. interrogans Pomona mozdok, 48B/470; L. interrogans Sejroe sejroe, Mus musculus 751/471. In accordance with the invention, the group of antigens is provided with an additional fifth strain of L. interrogans Canicola, No. 480 Udaloe, while as a result of the studies carried out, it was established that this additional strain in the composition of the experimental vaccine causes the formation of antibodies in protective titers of at least 1:100, which corresponds to the requirements applied to the concentrated inactivated liquid leptospirosis vaccine. A method for obtaining a polyvalent vaccine against human leptospirosis is presented, including the cultivation of the biomass of Leptospira on a liquid semi-synthetic storage medium with human blood proteins, inactivation with formaldehyde, concentration of the microbial mass by ultrafiltration on hollow polyamide fibers, purification of biomass from the components of the cultivation medium by double washing with physiological solution. In accordance with the invention, the standardization of microbial biomass was carried out by counting microbial cells, while the calculation was carried out according to the formula (1): , where K is the number of leptospira in 1 ml; 3570.4 - coefficient indicating how many times the area of distribution of the culture under glass exceeds the area of the field of view; 50 - coefficient indicating how many times the volume of 1 ml exceeds the volume of the test culture; M is the average number of leptospira in the field of view; analyzed five ampoules of the experimental vaccine, 0.02 ml each and viewed in the field of view of a dark-field microscope at a magnification of ×200; the result calculated by the formula was divided by 2, taking into account the dosage of the experimental vaccine and when determining the arithmetic mean value in a dose of 0.5 ml of the vaccine, which is not less than (20±2)×10⁶ microbial cells, it was concluded that the new experimental vaccine against leptospirosis meets the requirements, applied to the vaccine leptospirosis concentrated inactivated liquid used for the prevention of disease. The invention can be used to improve a multivalent vaccine against human leptospirosis.

EFFECT: creation of a multivalent, improved leptospirosis vaccine, concentrated inactivated liquid for people with increased epidemiological efficiency.

2 cl, 2 dwg