Patent Evaluation: A Two-Phase System for the Production of Antigens

Summary

Novelty: A hybrid live vaccine is disclosed. The vaccine comprizes a recombinant DNA producing subpopulations A and B. Subpopulation A is claimed to infect and act immunologically per se, whilst subpopulation B is claimed to be regenerated from subpopulation A, producing additional antigen and then acting immunologically with respect to this additional antigen. A process for the preparation of this live vaccine is also claimed. The vaccine has the potential for immunization of mammals.

Biology: Biological data include the results of oral immunizations of BALB/c mice with hybrid Salmonella typhimurium SL3235 strains and measuring hormonal immune response. The recombinant DNA is contained in a viral live vaccine, the chromosome of a cellular live vaccine or in a plasmid. The cellular live vaccine is a bacterium or a eukaryotic cell. The division of the live vaccine into the two subpopulations occurs by spontaneous DNA reorganization, based on a specific DNA inversion, deletion or replication process. The reorganization initiates a cascade reaction leading indirectly to the formation of additional antigen in subpopulation B.

Chemistry: Construction of an invertable DNA element for the production of Vibrio cholerae toxin 8-subunit antigen in Salmonella is described.