| Abstract: | Protective activity of anti-persussis rabbit and mouse sera and 19 S and 7 S fractions obtained from these sera was investigated in the test of passive protection of mice on a model of pertussis meningoencephalitis. The method of simultaneous intracerebral administration of the serum or fraction with live culture of a virulent B. pertussis strain was used. Hyperimmune rabbit serum containing mercaptoethanol-resistant agglutinins in a high titre was found to have the most pronounced protective effect. Serum of mice, collected 14 days after single immunization of the animals, did not show any protective properties. A small amount of protective activity was observed in the serum collected on the 30th day after a single administration of the vaccine. A sharp increase in the protective activity of the serum was observed after double immunization of mice. Correlation was found between the increase in the titre of agglutinins (in particular of 7 S antibodies) and the protective activity of the serum. Protective properties of 19 S and 7 S fractions isolated from immune rabbit and mouse sera by the method of gel filtration were investigated. Both fractions were found to possess protective properties, but fraction 7 S was more active than fraction 19 S. |
