H3N2 influenza virus HA and NA gene prevalence and variations in Shandong Province from 2023 to 2024
10.3969/j.issn.1002-2694.2025.00.117
- VernacularTitle:2023-2024年山东省H3N2流感病毒的流行及HA、NA基因变异特征分析
- Author:
Julong WU
1
;
Yujie HE
;
Lin SUN
;
Shu ZHANG
;
Shaoxia SONG
;
Ti LIU
;
Zhong LI
;
Xianjun WANG
;
Zengqiang KOU
Author Information
1. 山东省疾病预防控制中心,山东省传染病智慧化监测预警和防控重点实验室(筹),山东省预防医学研究院,济南 250014
- Publication Type:Journal Article
- Keywords:
H3N2;
hemagglutinin;
neuraminidase;
genetic mutation
- From:
Chinese Journal of Zoonoses
2025;41(8):873-878
- CountryChina
- Language:Chinese
-
Abstract:
This study investigated the epidemic status of H3N2 influenza virus and the genetic evolution characteristics of hemagglutinin(HA)and neuraminidase(NA)of H3N2 subtype influenza viruses isolated in Shandong Province during 2023-2024,to understand their compatibility with vaccine strains and drug resistance status.A total of 25 H3N2 subtype influenza virus strains were randomly selected from the strains isolated by the influenza surveillance network laboratory.The HA and NA genes were sequenced with the vaccine strains recommended by the WHO as a reference.Monitoring of sensitivity to oseltamivir and zanamivir was conducted through neuraminidase inhibition experiments.The H3N2 influenza viruses in Shandong Province belonged to the 3C.2a1b.2a.2a.3a.1 clade.Nucleotide sequence analysis revealed that the HA1 and NA genes were closely related to the WHO-recommended vaccine strain A/Darwin/9/2021 for the current season,with homology rates of 97.8%-98.2%and 98.9%-99.3%,respectively.Amino acid sequence analysis indicated 22 amino acid sequence variations in the HA1 protein,and antigenic drift was detected in 8 strains.A glycosylation site was added at position 94 of the HA protein in all 25 strains.Variations occurred in the NA antigenic determinants of some strains.Neuraminidase inhibition experiments indicated that all tested influenza viruses were sensitive to oseltamivir and zanamivir.Some differences in HA and NA proteins were observed between the monitored strains and vaccine strains.Continued monitoring of the molecular evolution characteristics of influenza viruses is necessary to understand the risk of influenza outbreaks,and their effects on the effectiveness of influenza vaccines and therapeutic drugs.
