Related Experiment Video
Updated: Jan 11, 2026

Expression and Purification of Virus-like Particles for Vaccination
Published on: June 2, 2016
Immunity to Influenza B/Yamagata-Lineage Viruses Has Not Waned Since the Disappearance of This Virus Lineage
Hassanein H Abozeid1,2, Chunyang Gu1, Sanja Trifkovic1
1Influenza Research Institute, Department of Pathobiological Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, USA.
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 declined since B/Yamagata viruses were last detected in the US in 2020. Human serum HI titers were highest against the first encountered B/Victoria- and B/Yamagata-lineage viruses, respectively, revealing imprinting effects.
Conclusions:
The recent disappearance of the B/Yamagata lineage has not led to a substantial decline in antibody levels against this lineage.
Related Concept Videos
Vaccinations
Immunological Memory
What is Immunological Memory?
Immunological memory is an integral function of the immune system that allows it to recognize and react more rapidly and effectively to pathogens previously encountered. This feature...
Leaky Scanning
Viral Recombination

