Giuseppe
Emeritus
J Virol. 2009 Oct 28. [Epub ahead of print]
Generation of live attenuated novel influenza A/California/7/09 (H1N1) vaccines with high yield in embryonated chicken eggs.
Chen Z, Wang W, Zhou H, Suguitan AL Jr, Shambaugh C, Kim L, Zhao J, Kemble G, Jin H. - MedImmune, 319 North Bernardo Ave, Mountain View, CA 94043.
Several live attenuated influenza A/California/7/09 (H1N1) candidate vaccine variants were generated by reverse genetics that possess the hemagglutinin (HA) and neuraminidase (NA) gene segments from A/California/7/09 (CA09) and six internal protein gene segments from the cold-adapted A/Ann Arbor/6/60 (H2N2) virus. The reassortant viruses replicated relatively poorly in embryonated chicken eggs. To improve virus growth in eggs, reassortants expressing the HA and NA of CA09 were passaged in MDCK cells and variants exhibiting large plaque morphology were isolated. These variants replicated at levels approximately 10-fold higher than the parental strains in embryonated chicken eggs. Sequence analysis indicated that single amino acid changes at positions 119, 153, 154, and 186 were responsible for the improved growth properties in MDCK cells and eggs. In addition, introduction of a mutation at residue 155, that was previously shown to enhance replication of a 1976 swine influenza virus, also significantly improved replication of the CA09 virus in eggs. Each variant was further evaluated for receptor binding preference, antigenicity, attenuation phenotype, and immunogenicity. Mutations at residues 153, 154, and 155 drastically reduced viral antigenicity, which made them unsuitable as vaccine candidates. However, changes at residues 119 and 186 did not affect virus antigenicity or immunogenicity, justifying their inclusion in live attenuated vaccine candidates to protect against the currently circulating 2009 swine-origin H1N1 viruses.
PMID: 19864389 [PubMed - as supplied by publisher]
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Generation of live attenuated novel influenza A/California/7/09 (H1N1) vaccines with high yield in embryonated chicken eggs.
Chen Z, Wang W, Zhou H, Suguitan AL Jr, Shambaugh C, Kim L, Zhao J, Kemble G, Jin H. - MedImmune, 319 North Bernardo Ave, Mountain View, CA 94043.
Several live attenuated influenza A/California/7/09 (H1N1) candidate vaccine variants were generated by reverse genetics that possess the hemagglutinin (HA) and neuraminidase (NA) gene segments from A/California/7/09 (CA09) and six internal protein gene segments from the cold-adapted A/Ann Arbor/6/60 (H2N2) virus. The reassortant viruses replicated relatively poorly in embryonated chicken eggs. To improve virus growth in eggs, reassortants expressing the HA and NA of CA09 were passaged in MDCK cells and variants exhibiting large plaque morphology were isolated. These variants replicated at levels approximately 10-fold higher than the parental strains in embryonated chicken eggs. Sequence analysis indicated that single amino acid changes at positions 119, 153, 154, and 186 were responsible for the improved growth properties in MDCK cells and eggs. In addition, introduction of a mutation at residue 155, that was previously shown to enhance replication of a 1976 swine influenza virus, also significantly improved replication of the CA09 virus in eggs. Each variant was further evaluated for receptor binding preference, antigenicity, attenuation phenotype, and immunogenicity. Mutations at residues 153, 154, and 155 drastically reduced viral antigenicity, which made them unsuitable as vaccine candidates. However, changes at residues 119 and 186 did not affect virus antigenicity or immunogenicity, justifying their inclusion in live attenuated vaccine candidates to protect against the currently circulating 2009 swine-origin H1N1 viruses.
PMID: 19864389 [PubMed - as supplied by publisher]
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