Evolution of Influenza A(H3N2) Viruses in 2 Consecutive Seasons of Genomic Surveillance, 2021

Evolution of Influenza A(H3N2) Viruses in 2 Consecutive Seasons of Genomic Surveillance, 2021–2023

Published:2023-11-16 Issue:12 Volume:10 Page:
ISSN:2328-8957
Container-title:Open Forum Infectious Diseases
language:en
Short-container-title:

Author:

Fall Amary¹,Han Lijie¹,Yunker Madeline¹,Gong Yu-Nong²³⁴⁵^ORCID,Li Tai-Jung²³,Norton Julie M¹,Abdullah Omar¹,Rothman Richard E⁶,Fenstermacher Katherine Z J⁶,Morris C Paul¹⁷,Pekosz Andrew⁶⁸,Klein Eili⁶⁹,Mostafa Heba H¹

Affiliation:

1. Division of Medical Microbiology, Department of Pathology, Johns Hopkins School of Medicine , Baltimore, Maryland , USA

2. Research Center for Emerging Viral Infections, College of Medicine, Chang Gung University , Taoyuan , Taiwan

3. International Master Degree Program for Molecular Medicine in Emerging Viral Infections, College of Medicine, Chang Gung University , Taoyuan , Taiwan

4. Department of Laboratory Medicine, Linkou Chang Gung Memorial Hospital , Taoyuan , Taiwan

5. National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes , Zhunan , Taiwan

6. Department of Emergency Medicine, Johns Hopkins School of Medicine , Baltimore, Maryland , USA

7. Integrated Research Facility, Division of Clinical Research, National Institute of Allergy and Infectious Diseases, National Institutes of Health , Frederick, Maryland , USA

8. W.Harry Feinstone Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health , Baltimore, Maryland , USA

9. Center for Disease Dynamics, Economics, and Policy , Washington, District of Columbia , USA

Abstract

Abstract Background The circulation and the genomic evolution of influenza A(H3N2) viruses during the 2021/2022 and 2022/2023 seasons were studied and associated with infection outcomes. Methods Remnant influenza A–positive samples following standard-of-care testing from patients across the Johns Hopkins Health System (JHHS) were used for the study. Samples were randomly selected for whole viral genome sequencing. The sequence-based pEpitope model was used to estimate the predicted vaccine efficacy (pVE) for circulating H3N2 viruses. Clinical data were collected and associated with viral genomic data. Results A total of 121 683 respiratory specimens were tested for influenza at JHHS between 1 September 2021 and 31 December 2022. Among them, 6071 (4.99%) tested positive for influenza A. Of these, 805 samples were randomly selected for sequencing, with hemagglutinin (HA) segments characterized for 610 samples. Among the characterized samples, 581 were H3N2 (95.2%). Phylogenetic analysis of HA segments revealed the exclusive circulation of H3N2 viruses with HA segments of the 3C.2a1b.2a.2 clade. Analysis of a total of 445 complete H3N2 genomes revealed reassortments; 200 of 227 of the 2022/2023 season genomes (88.1%) were found to have reassorted with clade 3C.2a1b.1a. The pVE was estimated to be −42.53% for the 2021/2022 season and 30.27% for the 2022/2023 season. No differences in clinical presentations or admissions were observed between the 2 seasons. Conclusions The increased numbers of cases and genomic diversity of influenza A(H3N2) during the 2022/2023 season were not associated with a change in disease severity compared to the previous influenza season.

Funder

Johns Hopkins Center of Excellence in Influenza Research and Surveillance

Publisher

Oxford University Press (OUP)

Subject

Infectious Diseases,Oncology

Link

https://academic.oup.com/ofid/advance-article-pdf/doi/10.1093/ofid/ofad577/53475800/ofad577.pdf

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