Prevalence of Influenza B/Yamagata Viruses From Season 2012/2013 to 2021/2022 in Italy as an Indication of a Potential Lineage Extinction.

Autor: Marchi S; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy., Bruttini M; Tuscan Centre of Precision Medicine, Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy., Milano G; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy., Manini I; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy., Chironna M; Department of Interdisciplinary Medicine, University of Bari Aldo Moro, Bari, Italy., Pariani E; Department of Biomedical Sciences for Health, University of Milan, Milan, Italy., Manenti A; VisMederi srl, Siena, Italy., Kistner O; VisMederi srl, Siena, Italy., Montomoli E; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.; VisMederi srl, Siena, Italy.; VisMederi Research srl, Siena, Italy., Temperton N; Viral Pseudotype Unit, Medway School of Pharmacy, University of Kent and Greenwich Chatham Maritime, Kent, UK., Trombetta CM; Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy.; VisMederi Research srl, Siena, Italy.
Jazyk: angličtina
Zdroj: Influenza and other respiratory viruses [Influenza Other Respir Viruses] 2024 Sep; Vol. 18 (9), pp. e13359.
DOI: 10.1111/irv.13359
Abstrakt: Background: Influenza B/Yamagata viruses exhibited weak antigenic selection in recent years, reducing their prevalence over time and requiring no update of the vaccine component since 2015. To date, no B/Yamagata viruses have been isolated or sequenced since March 2020.
Methods: The antibody prevalence against the current B/Yamagata vaccine strain in Italy was investigated: For each influenza season from 2012/2013 to 2021/2022, 100 human serum samples were tested by haemagglutination inhibition (HAI) assay against the vaccine strain B/Phuket/3073/2013. In addition, the sequences of 156 B/Yamagata strains isolated during the influenza surveillance activities were selected for analysis of the haemagglutinin genome segment.
Results: About 61.9% of the human samples showed HAI antibodies, and 21.7% had protective antibody levels. The prevalence of antibodies at protective levels in the seasons between the isolation of the strain and its inclusion in the vaccine was between 11% and 25%, with no significant changes observed in subsequent years. A significant increase was observed in the 2020/2021 season, in line with the increase in influenza vaccine uptake during the pandemic. Sequence analysis showed that from 2014/2015 season onward, all B/Yamagata strains circulating in Italy were closely related to the B/Phuket/2013 vaccine strain, showing only limited amino acid variation.
Conclusions: A consistent prevalence of antibodies to the current B/Yamagata vaccine strain in the general population was observed. The prolonged use of a well-matched influenza vaccine and a low antigenic diversity of B/Yamagata viruses may have facilitated a strong reduction in B/Yamagata circulation, potentially contributing to the disappearance of this lineage.
(© 2024 The Author(s). Influenza and Other Respiratory Viruses published by John Wiley & Sons Ltd.)
Databáze: MEDLINE
Externí odkaz:
Nepřihlášeným uživatelům se plný text nezobrazuje