Work

Antigenic analysis of the influenza B virus hemagglutinin protein

Year: 2024

Type: article

Abstract: Background: Influenza B viruses (IBVs) primarily infect humans and are a common cause of respiratory infections in humans. We aimed to systematically analyze the antigenicity of the IBV hemagglutinin protein and provide a basis for finding a broader and more efficient IBV vaccine strain. Methods: Thirty-one B/Victoria and 19 B/Yamagata representative circulating strains were selected from GISAID, and pseudotyped viruses were constructed with the vesicular stomatitis virus system. We immunized guinea pigs with DNA vaccine following pseudotyped virus vaccines and monovalent inactivated vaccine stock of the IBV vaccine strains and tested neutralizing antibodies against the pseudotyped viruses. By comparing differences between various vaccine strains, we constructed several pseudotyped viruses that contained varying mutations based on vaccine strain BV-21. Findings: The vaccine strains had good neutralization levels against the epidemic virus strains of the same year, with neutralization titers ranging from 370 to 840 and decreasing 1–10-fold as the year became more distant. Each of the high-frequency epidemic strains of B/Victoria and B/Yamagata not only induced high neutralizing titers as immunogens but also had broadly neutralizing effects against endemic virus strains from different years, with a neutralizing titer range of 1000–7200. R156G, D209N, and R215K were identified as affecting the antigenicity of IBV. Interpretation: This study not only used pseudotyped virus technology to monitor the cross-neutralizing efficacy of high-frequency epidemic strains and vaccine strains recommended by the World Health Organization but also identified three mutation sites that seriously affect the antigenicity of B/Victoria vaccine strains. These mutation sites provide reference data for the selection and design of a universal IBV vaccine strain in the future.

Source: Virologica Sinica

DOI: 10.1016/j.virs.2024.08.012