tetano
Editor, Senior Moderator
Influenza Other Respir Viruses
. 2025 Nov;19(11):e70188.
doi: 10.1111/irv.70188. Immunity to Influenza B/Yamagata-Lineage Viruses Has Not Waned Since the Disappearance of This Virus Lineage
Hassanein H Abozeid[SUP] 1 2 [/SUP], Chunyang Gu[SUP] 1 [/SUP], Sanja Trifkovic[SUP] 1 [/SUP], Gabriele Neumann[SUP] 1 [/SUP], Yoshihiro Kawaoka[SUP] 1 3 4 5 [/SUP]
Affiliations
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.
Keywords: B/Yamagata lineage; antibody waning; influenza B virus.
. 2025 Nov;19(11):e70188.
doi: 10.1111/irv.70188. Immunity to Influenza B/Yamagata-Lineage Viruses Has Not Waned Since the Disappearance of This Virus Lineage
Hassanein H Abozeid[SUP] 1 2 [/SUP], Chunyang Gu[SUP] 1 [/SUP], Sanja Trifkovic[SUP] 1 [/SUP], Gabriele Neumann[SUP] 1 [/SUP], Yoshihiro Kawaoka[SUP] 1 3 4 5 [/SUP]
Affiliations
- PMID: 41243269
- DOI: 10.1111/irv.70188
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.
Keywords: B/Yamagata lineage; antibody waning; influenza B virus.