Volume 25, Number 1—January 2019
Association of Increased Receptor-Binding Avidity of Influenza A(H9N2) Viruses with Escape from Antibody-Based Immunity and Enhanced Zoonotic Potential
|HA backbone and substitution||Fold change in HI titer (titer)†|
|R162Q + D262N||– (2,048)|
|A180T + K164N||4 (128)|
*Postinfection polyclonal antiserum raised in a single chicken inoculated with UDL-01/08 was used in all HI assays. Amino acid substitutions were introduced into a contemporary virus HA backbone (SKP-827/16 with A180) or the UDL-01/08 HA backbone and rescued by reverse genetics. HI titers between contemporary viruses and UDL-01/08 virus were compared. HA, hemagglutinin; HI, hemagglutination inhibition; –, no change.
†The homologous HI titer for UDL-01/08 antiserum was 2,048.
‡Indicates fold decrease compared with UDL-01/08.
1Current affiliation: Imperial College London, London, UK.
2Current affiliation: Chinese Academy of Agricultural Sciences, Beijing, China.