-

nihao guest [ sign in / register ]
2020-8-11 0:26:40


Kato-Miyashita S, et al. Antigenic variants of influenza B viruses isolated in Japan during the 2017-2018 and 2018-2019 influenza seasons. Influenza Other Respir Viruses. 2020 Jan 19.
submited by kickingbird at Jan, 20, 2020 23:20 PM from Influenza Other Respir Viruses. 2020 Jan 19.

BACKGROUND:
Here, we genetically and antigenically analyzed influenza B viruses (IBVs) isolated in Japan during the 2017-2018 and 2018-2019 influenza seasons.
METHODS:
A total of 68 IBVs (61 B/Yamagata/16/88-like [B/Yamagata]-lineage and 7 B/Victoria/2/87-like [B/Victoria]-lineage) were antigenically and genetically characterized by using hemagglutination inhibition (HI) assays and phylogenetic analysis, respectively. The susceptibility of IBVs to neuraminidase (NA) inhibitors was assessed by using a fluorescence-based NA inhibition assay.
RESULTS:
All 61 B/Yamagata-lineage isolates were genetically closely related to B/Phuket/3073/2013, the vaccine strain for these two seasons. Eleven B/Yamagata-lineage isolates tested were antigenically similar to B/Phuket/3073/2013 by the HI test. Seven B/Victoria-lineage isolates were genetically closely related to B/Texas/02/2013, the WHO-recommended vaccine strain for the 2017-2018 season; however, they were antigenically distinct from B/Texas/02/2013 with an eightfold or 16-fold difference in HI titer. Of these 7 isolates, 4 possessed a two-amino-acid deletion at positions 162 and 163 in hemagglutinin (HA) and the other 3 had a three-amino-acid deletion at positions 162-164 in HA. Importantly, the variants with the three-amino-acid deletion appeared to be antigenically different from the B/Colorado/06/2017 virus with the two-amino-acid deletion, the vaccine strain for the 2018-2019 season with a fourfold or eightfold difference in HI titer. One B/Yamagata-lineage isolate carrying a G407S mutation in its NA showed a marked reduction in susceptibility to zanamivir, peramivir, and laninamivir.
CONCLUSIONS:
These results highlight the need for continued monitoring for the prevalence of the antigenic variant with the three-amino-acid deletion and the variant with reduced NA inhibitor susceptibility.

See Also:

Latest articles in those days:

[Go Top]    [Close Window]

Related Pages:
Learn about the flu news, articles, events and more
Subscribe to the weekly F.I.C newsletter!


  

Site map  |   Contact us  |  Term of use  |  FAQs
Copyright ©www.flu.org.cn. 2004-2020. All Rights Reserved. Powered by FIC 4.0.1
  Email:webmaster@flu.org.cn