Single amino acid substitutions in the hemagglutinin of influenza A/Singapore/21/04 (H3N2) increase virus growth in embryonated chicken eggs.
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.
Lu
Bin
B
MedImmune Vaccines, Inc., 297N. Bernardo Avenue, Mountain View, CA 94043, USA. lub@medimmune.com
Zhou
Helen
H
Chan
Winnie
W
Kemble
George
G
Jin
Hong
H
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*
D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus