Abstract: There is disclosed an antigen comprising an amino acid sequence of the suce antigen of a hepatitis B virus. The present antigen can be produced easily and safely at low cost by means of recombinant DNA technique. The present antigen can be used as an effective vaccine and diagnostic for hepatitis B.

Abstract: There is provided a recombinant Marek's disease virus comprising the genomic DNA of an attenuated Marek's disease virus and a foreign gene from another source. The present recombinant virus can advantageously be used as an active ingredient for a multifunctional live vaccine, exhibiting not only the antigenicity and immunogenicity of the Marek's disease virus but also the properties ascribed to the foreign gene. Since the suitable host cell for the recombinant virus of the present invention is an avian cell which is available in a large quantity and not expensive, the recombinant virus of the present invention can be produced efficiently at low cost on a commercial scale.

Abstract: There is disclosed a method for culturing Bordetella pertussis in the presence of a cellulose and/or cellulose derivatives. The present method is useful for obtaining a mixed antigen comprising pertussis toxin and filamentous hemagglutinin in a large amount at low cost. From the antigen, there can be obtained a stable and effective pertussis toxoid to be used for a pertussis vaccine. There is also disclosed a vaccine comprising the pertussis toxoid as an active ingredient and a gelatin and/or gelatin derivatives as a stabilizing agent. The present vaccine is extremely stable and can be stored for a prolonged period of time.

Abstract: There is disclosed a method for purifying a gene-expression product produced by recombinant DNA technique which comprises a specific sequence of steps including adsorption treatment with silica gel, adsorption treatment with activated carbon, at least twice density gradient centrifugation and at least twice equilibrium density gradient centrifugation. The method of the present invention is very effective to remove allergen from gene-expression products contaminated therewith, enabling highly purified gene-expression products to be produced on a large scale.

Abstract: There is disclosed a method for culturing Bordetella pertussis in the prece of a cellulose and/or cellulose derivatives. The present method is useful for obtaining a mixed antigen comprising pertussis toxin and filamentous hemagglutinin in a large amount at low cost. From the antigen, there can be obtained a stable and effective pertussis toxoid to be used for a pertussis vaccine. There is also disclosed a vaccine comprising the pertussis toxoid as an active ingredient and a gelatin and/or gelatin derivatives as a stabilizing agent. The present vaccine is extremely stable and can be stored for a prolonged period of time.