Genetic characteristics of influenza A H3N2 virusin Ma'anshan City in 2022 - 2024
10.3969/j.issn.1006-2483.2026.03.007
- VernacularTitle:2022—2024年马鞍山市甲型H3N2流感病毒的基因特征分析
- Author:
Rong WANG
1
;
Zikun YANG
1
;
Zhibin SHEN
1
;
Chen YANG
1
;
Xiaofang ZHU
1
;
Liangliang JIANG
1
;
Ying HONG
1
Author Information
1. Ma'anshan Center for Disease Control and Prevention（Ma'anshan Municipal Health Supervision Institute）, Ma'anshan, Anhui 243011, China
- Publication Type:Journal Article
- Keywords:
Influenza A;
H3N2;
HA gene;
NA gene;
Genetic analysis
- From:
Journal of Public Health and Preventive Medicine
2026;37(3):34-38
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze the genetic characteristics and variations of influenza A (H3N2) viruses in Ma'anshan from 2022 to 2024, and to provide a scientific basis for local influenza prevention and control. Methods From April 2022 to March 2024, influenza-like illness (ILI) specimens were collected from three national influenza surveillance sentinel hospitals in Ma’anshan. Samples positive for influenza by real-time PCR were subjected to virus culture and identification. A total of 40 representative A/H3N2 strains with hemagglutination titers ≥8 were selected for whole-genome sequencing. Genetic evolution, homology, amino acid variations, and glycosylation sites were analyzed. Results All H3N2 representative strains from the 2022–2023 influenza season belonged to clade 3C.2a1b.2a.1a.1, while those from the 2023–2024 season fell into clade 3C.2a1b.2a.2a.3a.1. The nucleotide and amino acid sequence similarities of HA and NA between the 40 representative strains and the vaccine strain A/Darwin/6/2021 were all above 97.35%. Compared with the vaccine strain, amino acid mutations were identified in antigenic sites A, B, C, and E, as well as in receptor-binding sites of the HA protein. An I222V substitution was detected in the NA protein. The HA protein contained four additional glycosylation sites compared to the vaccine strain, while the glycosylation pattern of the NA protein remained consistent. Conclusion No antigenic drift was observed in the influenza A/H3N2 viruses in Ma'anshan City from 2022 to 2024, but genetic changes such as branching variations, key amino acid substitutions, and an increase in HA glycosylation sites were observed. These findings underscore the importance of sustained molecular surveillance of local influenza viruses.
