Using the microscopic agglutination test (MAT), the induction of antibodies against Leptospira sp. p was conducted in vaccinated cattle with a commercial polyvalent vaccine. The homologous serological response was determined by MAT using two vaccinations schemes. The animals used were adult milking cows from six properties in the Northwest Region of the São Paulo State, Brazil. From each herd 20 animals were used, selected after three consecutive tests with 20-day intervals, based on a serological screening with 24 antigens serovars of Leptospira spp. The experimental groups were constituted by non-reagent animals (groups I, II and III), and reagent animals (groups IV, V and VI). Later the animals were subdivided into control groups (I and IV), groups that received one dosis of vaccine (II and IV) and groups that received one dosis with booster 30 day after the first injection (III and VI). The MAT test was conducted evaluating the animals at the days 0, 15, 30, 45 and 60 from the first injection of the vaccine. The results have shown no significant titre difference (p>0.05) between vaccinated and non-vaccinated animals. There was no significant difference (p>0.05) in the responses of vaccine titres related to the serological profile of the animals. The vaccination with booster presented the best response inducing the production of agglutinins only for the hardjo, wolffi, icterohaemorrhagiae and pomona serovars. Additional trials and validation of immunogenic power of the vaccine used in this research is necessary.
leptospirosis; bovine; vaccination
