The authors examined CBA mice infected with a virulent culture (H37 Rv), BCG-vaccinated mice and intact mice and rabbits infected with a virulent culture Bovinus-8 after preliminary sensitization. It was established that the level of antituberculous antibodies in the enzyme-linked immunoassay was higher in H37 Rv infected mice than in BCG-vaccinated animals (regardless of the used antigen, the ultrasonic disintegrator BCG or H37 Rv). The spectrum of antituberculous antibodies was different in the infected and vaccinated mice, the infected mice showed additional bands in the 20 kD area. The level of antituberculous antibodies was higher in rabbits with a limited process than in those with a disseminated process. With the latter, antibodies to antigenic determinants that had lower molecular weight (25-35 kD) were detectable.