ABSTRACT
The method for the two-cycle cultivation of V. cholerae, reference strains Inaba and Ogawa, in a fermenter has been developed. In the first and second cultivation cycles no difference in the yield of the biomass and in the ultrastructure of the vibrios has been established. In the second cycle a decrease in the minimum time of generation has been observed. The vaccines obtained in the first and second cultivation cycles have not been found to differ in their antigenic and immunogenic activity. The vaccines meet the WHO requirements.
Subject(s)
Fermentation , Vibrio cholerae/growth & development , Animals , Antibodies, Bacterial/analysis , Antigens, Bacterial/immunology , Bacterial Vaccines/immunology , Bacteriological Techniques/instrumentation , Mice , Microscopy, Electron , Time Factors , Vibrio cholerae/immunology , Vibrio cholerae/ultrastructureABSTRACT
The analysis of the morbidity and mortality rates in diphtheria, tetanus and pertussis in Bulgaria after the introduction of the compulsory mass immunization of children with combined DPT vaccine is presented. These data indicate that morbidity in diphtheria, tetanus and pertussis has sharply decreased. Favorable results with respect to these three diseases are the consequence of the complete coverage of the child population by immunization with the vaccine whose quality has been steadily improving for the last 20 years. A higher purity of toxoids has been achieved, and at present it exceeds the latest WHO requirements. Pertussis vaccine is produced with the use of strains whose serological characteristics correspond to those of the pertussis strains circulating in the country. The study of the reactogenicity of DPT vaccine, carried out over the period of 20 years, has shown that the vaccine has low reactogenicity.
Subject(s)
Diphtheria/prevention & control , Tetanus/prevention & control , Whooping Cough/prevention & control , Adolescent , Bulgaria , Child , Child, Preschool , Diphtheria/epidemiology , Diphtheria Toxoid/administration & dosage , Diphtheria Toxoid/adverse effects , Diphtheria Toxoid/standards , Diphtheria-Tetanus-Pertussis Vaccine , Dose-Response Relationship, Immunologic , Drug Combinations/administration & dosage , Drug Combinations/adverse effects , Drug Combinations/standards , Humans , Immunization, Secondary , Infant , Pertussis Vaccine/administration & dosage , Pertussis Vaccine/adverse effects , Pertussis Vaccine/standards , Tetanus/epidemiology , Tetanus Toxoid/administration & dosage , Tetanus Toxoid/adverse effects , Tetanus Toxoid/standards , Whooping Cough/epidemiologyABSTRACT
The cultivation of V. cholerae was carried out in casein broth in a fermenter. 2 kinds of cultivation conditions were compared. The results thus obtained indicate that the cultivation of V. cholerae under the conditions of the controlled level of dissolved oxygen (pO2--50%) ensures the optimum conditions for proliferation and the high yield of biomass; it also allows obtaining vaccine whose immunogenic properties are not inferior to those of the WHO reference vaccine.
