Abstract: The present invention provides virus-like particles (VLP) highly secreting or producing signal peptide obtained by altering a signal sequence derived from West Nile virus (WNV), the signal peptide, a WNV VLP secretion expression vector containing a nucleic acid encoding prM protein and E protein, a WNP VLP highly secreting or producing animal cell line harboring the vector, a WNV vaccine containing WNV VLP obtained by the cell line as an active ingredient, and a WNV DNA vaccine containing the VLP secretion expression vector as an active ingredient.

Abstract: The invention provides virus-like particles (VLP) highly secreting or producing signal peptide obtained by altering a signal sequence derived from West Nile virus (WNV), the signal peptide, a WNV VLP secretion expression vector containing a nucleic acid encoding prM protein and E protein, a WNP VLP highly secreting or producing animal cell line harboring the vector, a WNV vaccine containing WNV VLP obtained by the cell line as an active ingredient, and a WNV DNA vaccine containing the VLP secretion expression vector as an active ingredient.

Abstract: A nucleic acid molecule containing nucleotide sequences that encode the capsid protein, pre-membrane protein and non-structural protein of Japanese encephalitis virus, and a nucleotide sequence that encodes the envelop protein of a second flavivirus, wherein the nucleotide sequence(s) that encode(s) the pre-membrane protein and/or non-structural protein of Japanese encephalitis virus contain(s) nucleotide mutations that produce one or more amino acid mutations that attenuate the virus.

Abstract: The present invention provides virus-like particles (VLP) highly secreting or producing signal peptide obtained by altering a signal sequence derived from West Nile virus (WNV), the signal peptide, a WNV VLP secretion expression vector containing a nucleic acid encoding prM protein and E protein, a WNP VLP highly secreting or producing animal cell line harboring the vector, a WNV vaccine containing WNV VLP obtained by the cell line as an active ingredient, and a WNV DNA vaccine containing the VLP secretion expression vector as an active ingredient.

Abstract: A nucleic acid molecule containing nucleotide sequences that encode the capsid protein, pre-membrane protein and non-structural protein of Japanese encephalitis virus, and a nucleotide sequence that encodes the envelop protein of a second flavivirus, wherein the nucleotide sequence(s) that encode(s) the pre-membrane protein and/or non-structural protein of Japanese encephalitis virus contain(s) nucleotide mutations that produce one or more amino acid mutations that attenuate the virus.

Abstract: A nucleic acid molecule containing nucleotide sequences that encode the capsid protein, pre-membrane protein and non-structural protein of Japanese encephalitis virus, and a nucleotide sequence that encodes the envelop protein of a second flavivirus, wherein the nucleotide sequence(s) that encode(s) the pre-membrane protein and/or non-structural protein of Japanese encephalitis virus contain(s) nucleotide mutations that produce one or more amino acid mutations that attenuate the virus.

Abstract: A nucleic acid molecule containing nucleotide sequences that encode the capsid protein, pre-membrane protein and non-structural protein of Japanese encephalitis virus, and a nucleotide sequence that encodes the envelop protein of a second flavivirus, wherein the nucleotide sequence(s) that encode(s) the pre-membrane protein and/or non-structural protein of Japanese encephalitis virus contain(s) nucleotide mutations that produce one or more amino acid mutations that attenuate the virus.

Abstract: The present invention provides a novel inactivated virus particle and a reinforced immunogen which have a reinforced titer about twice to about 10 times that of a conventional vaccine, as well as a method for producing the same. The inactivated virus particle is produced by inactivating and then purifying a culture by physical means. The inactivated virus particle of the present invention is useful in a diagnostic agent for infectious disease caused by a group of Japanese encephalitis virus.

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.