Phylogenetic and antigenic analysis on hemagglutinin gene of influenza B virus (Victoria) in 2023-2024 surveillance season in Beijing
10.3760/cma.j.cn112866-20240329-00047
- VernacularTitle:2023—2024年流感监测季北京市乙型Victoria系流感病毒血凝素基因特性和抗原性分析
- Author:
Guilan LU
1
;
Jiachen ZHAO
;
Weixian SHI
;
Li ZHANG
;
Yimeng LIU
;
Zhaomin FENG
;
Ying SUN
;
Daitao ZHANG
;
Xiaomin PENG
Author Information
1. 北京市疾病预防控制中心传染病地方病控制所，北京 100013
- Keywords:
Influenza B virus;
Hemagglutinin gene;
Genetic mutation;
Phylogenic analysis;
Antigenic analysis
- From:
Chinese Journal of Experimental and Clinical Virology
2024;38(4):415-421
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To disclose phylogenetic and antigenic characteristics of hemagglutinin (HA) gene of influenza B virus (Victoria) (BV) in the 2023-2024 influenza surveillance season in Beijing, and understand the matching with influenza vaccine component strain.Methods:Pharyngeal swab specimens from influenza like-illness (ILI) in the 2023-2024 influenza surveillance season were collected from surveillance network labs in Beijing and BV strains were isolated through MDCK or chicken embryo culture. After extracting nucleic acid, HA gene was amplified and sequenced. The nucleotide and amino acid sequence identity were conducted and the maximum likelihood method in Mega 5.0 software was used to construct the phylogenetic tree of HA gene. N-glycosylation sites of HA were performed online. Furthermore, three-dimensional structure of HA was available from SWISS-MODEL homologous modeling. Hemagglutination inhibition (HI) tests were performed to analyze antigenic characteristics of HA of BV strains.Results:Fifty-four BV strains were randomly selected to be analyzed further. Compared with the HA gene of this influenza season vaccine strain (B/Austria/1359417/2021), there are three amino acid mutations among all BV strains, two of which are located in two different antigenic determinants. Furthermore, the phylogenetic tree analysis revealed that only one subgroup of 1A.3a.2 was circulating simultaneously. All BV strains are located in Clade 1A.3a.2 subgroup, and in the same subgroup with that of the vaccine component BV strain in 2023-2024. All BV strains have the same glycosylation sites as that of the vaccine component BV strain in 2023-2024. Antigenic analysis showed that all BV strains were antigenically similar with its vaccine strain.Conclusions:In the 2023-2024 influenza surveillance season, the prevalent BV strains in the population in Beijing city are located in Clade 1A. 3a. 2 subgroup. The antigen matching between BV epidemic strains and vaccine BV components is relatively high during this surveillance season.
