Immunity to Influenza B/Yamagata-Lineage Viruses Has Not Waned Since the Disappearance of This Virus Lineage.

ABSTRACT:

Background

Influenza B viruses are important contributors to seasonal influenza epidemics. Two antigenically distinct lineages, B/Victoria and B/Yamagata, have been circulating since the late 1980s. However, the B/Yamagata lineage has not been detected in most countries since 2020, potentially resulting in waning immunity that may leave people vulnerable to B/Yamagata virus infections, should this lineage reemerge.

Methods

We investigated the impact of the recent lack of B/Yamagata virus circulation on immunity in adults by analyzing the hemagglutination-inhibition (HI) titers of serum samples (n = 504) collected from 2013 through 2024 against influenza B viruses circulating from 1958 to 2019.

Results

Human serum HI titers to B/Yamagata viruses have not markedly decli

SUBMITTER: Abozeid HH 

PROVIDER: S-EPMC12620126 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature