Evaluation of the efficacy of human antimeningococcal immunoglobulin G in infant rats experimentally infected with Neisseria meningitidis group B.

Infants rats, a well known model for the experimental reproduction of bacterial meningitis, were used by us to test the protective potential of antibodies developed in humans who had been vaccinated with the Cuban antimeningitis vaccine (VA-MENGOCBC). Newborn rats were inoculated by the intraperitoneal and intranasal routes with suspensions of Neisseria meningitidis group B bacteria. Bacteremia kinetics were evaluated from blood and brain-spinal fluid cultures. Samples of the central nervous system were taken and smears of backbone fluids prepared for histopathologic evaluations. Characterization of bacteremia evolution, as well as the mean lethal dose of germs and histopathologic features, were determined. After standardization of the model, therapeutic schemes were applied using passive immunization pre- and post-infection with N. meningitidis. A significant level of protection was obtained in relation to control animals that received the same challenge doses.