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The elevated world incidence of meningococcal meningitis due to Neisseria meningitidis B (N. meningitidis) has mobilized scientists in the search for a speedy solution to this problem. In order to study this disease, it is indispensable to develop experimental models which will enable the characterization of, not only the immunogenic and protective capability of vaccine candidates, but also the possible toxicity of the preparation. Consequently, a Balb/c mouse model was used, together with virulence stimulating factors, in order to achieve the experimental development of the disease. Different vaccine dose schedules and dilutions were used (½, ¼, 1/8, 1/16) in 0,85% physiologic saline solution. Fifteen groups of 8 animals each, which had previously received Ferric Dextran (IMEFA) and swine gastric mucin (8%) in a total volume of 0,4 mL and a control group which received the pure vaccine were formed. N. meningitidis Strain 385, was used for the challenge, with an inoculum concentration of 107 UFC/mL. The following vaccination schedule was observed: the groups of animals were vaccinated with 1, 2 and 3 doses on days: 0, 15 and 30. A total of 0,2 mL of the N. meningitidis inoculum was administered intraperitoneally. The half lethal dose (LD 50), bactericidal antibodies and serological response using an ELISA assay were determined and the protection conferred by the prepartions were calculated. The Log rank method was used for comparing survival time. The SPLINE surface adjustment method was used in the case of the ELISA assay. The usefulness of the Balb/c mouse biomodel for comparing the efficacy of the VA-MENGOC-BC® vaccine was demonstrated. The correlation between the different levels of antibodies and the protection conferred by the vaccine was demonstrated and verified by challenge assays. An approximation of the efficacy limit of VA-MENGOC-BC® was obtained by means of consecutive dilutions of the product in the Balb/c mouse line. [ABSTRACT FROM AUTHOR]

Considering that the expected immunization schedule for man includes three doses of VA-DIFTET, once demonstrated that this vaccine is safe for two animal species, the study of its toxicity by repeated dosing in mice was imperative, taking into account that in humans a three-dose schedule is used when the pertusis component is contraindicated. Two-hundred and ten OF1 mice of both sexes were used. Experimental groups were similar to those used in the single-dose toxicity study: duplex vaccine, diphtheria toxoid, tetanus toxoid, adjuvant, thiomersal, physiologic saline solution), and a non-treated control group. One group of male and another of female mice were randomly assigned to each treatment to receive 1, 2 or 3 intramuscular doses. Clinical symptoms, body weight increase, water and food intakes and the antibody titers (IgG by indirect ELISA) against the tetanus and diphtheria toxoids were evaluated after each administration. Finally, all mice were sacrificed and anatomopathological studies performed. The relative indexes of spleen and thymus and the spleen/thymus rate were also studied post-mortem. No evidence of toxicity was observed; however, those mice inoculated with the vaccine or the toxoids showed a significant immune response. Final results were considered satisfactory. [ABSTRACT FROM AUTHOR]

Several animals models for Haemophilus influenzae type b (Hib) meningitis are available. Infant rats have resulted the best as a challenge model and Guinea pigs have been particularly useful for vaccine power tests. The aim of the present work was developing a new model based on the use of Duncan Hartley Guinea pigs. Adult animals of both sexes, weighing over 450 g were currently inoculated with Hib (104 1010 CFU) and different concentrations of iron dextran as a virulence enhancement agent. High mortality rates and prolonged bacteremic states were achieved, even with the lowest bacterial dose inoculated. The clinical course was less acute than in previously reported models. Besides, anatomopathological findings were more exuberant and indicative of the natural pathogeny of the disease. Results suggest that a potentially useful animal model for the evaluation of vaccines and sera has been achieved. [ABSTRACT FROM AUTHOR]

Since 1995, in our Institute we have been working on a project to produce the typhoid Vi polysaccharide vaccine in Cuba. During the research stage we obtained all the operation and control parameters in the different steps of the process, in this way enabling its characterization and obtaining the necessary equations to define the operation and control parameters for industrial scaling-up. Similar geometrically and dynamically systems were guaranteed, thus achieving similar results for the research stage, as well as for the production one. Also, three consecutive batches of final vaccine (8001, 8002, 8003) were produced and they fulfilled the quality specifications established by the World Health Organization ( WHO ) for this product. [ABSTRACT FROM AUTHOR]