title: Single amino acid substitutions in the hemagglutinin of influenza A/Singapore/21/04 (H3N2) increase virus growth in embryonated chicken eggs.
abstract: Most of the recently circulating H3N2 influenza A strains do not replicate well in embryonated chicken eggs and had to be isolated by cell culture, which presents a great challenge for influenza vaccine production using embryonated chicken eggs. We previously reported that a human H3N2 virus, A/Fujian/411/02, which replicates poorly in eggs, could be improved by changing a minimum of two HA residues (G186V/V226I or H183L/V226A). Here, we extended our work to the A/Singapore/21/04 strain that was also unable to grow in eggs. We showed that a single amino acid substitution of either G186V or A196T in the HA resulted in significantly increased virus replication in eggs without affecting virus antigenicity.
authors.affiliation: MedImmune Vaccines, Inc., 297N. Bernardo Avenue, Mountain View, CA 94043, USA. lub@medimmune.com
authors.forename: Bin
authors.initials: B
authors.lastname: Lu
authors.forename: Helen
authors.initials: H
authors.lastname: Zhou
authors.forename: Winnie
authors.initials: W
authors.lastname: Chan
authors.forename: George
authors.initials: G
authors.lastname: Kemble
authors.forename: Hong
authors.initials: H
authors.lastname: Jin
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D000956:Antigens, Viral / Q000235:genetics; D002645:Chickens; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics* / Q000378:metabolism; D053122:Influenza A Virus, H3N2 Subtype / Q000235:genetics / Q000254:growth & development* / Q000502:physiology; D014776:Virus Cultivation / Q000379:methods*; D014779:Virus Replication; D015053:Zygote / Q000821:virology*
chemical_list: D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus