{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,11,12]],"date-time":"2026-11-12T15:55:46Z","timestamp":1794498946114,"version":"4.9.1"},"reference-count":33,"publisher":"BMJ","issue":"1","license":[{"start":{"date-parts":[[2023,7,24]],"date-time":"2023-07-24T00:00:00Z","timestamp":1690156800000},"content-version":"unspecified","delay-in-days":23,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"crossref","award":["2022ZFJH003"],"award-info":[{"award-number":["2022ZFJH003"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"crossref"}]},{"DOI":"10.13039\/501100012226","name":"Fundamental Research Funds for the Central Universities","doi-asserted-by":"crossref","award":["K20210205"],"award-info":[{"award-number":["K20210205"]}],"id":[{"id":"10.13039\/501100012226","id-type":"DOI","asserted-by":"crossref"}]},{"name":"Mega-Project of National Science and Technology for the 13th Five-Year Plan of China","award":["2018ZX10715013-003-003"],"award-info":[{"award-number":["2018ZX10715013-003-003"]}]},{"name":"Mega-Project of National Science and Technology for the 13th Five-Year Plan of China","award":["2018ZX10721102-003-006"],"award-info":[{"award-number":["2018ZX10721102-003-006"]}]},{"name":"Technological Innovation Leading Talents of \u201cTen Thousand Talents Plan\u201d of Zhejiang Province","award":["2020R52010"],"award-info":[{"award-number":["2020R52010"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["71904170"],"award-info":[{"award-number":["71904170"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Zhejiang University K. P. Chao's High Technology Development Foundation","award":["2022RC017"],"award-info":[{"award-number":["2022RC017"]}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open Resp Res"],"accepted":{"date-parts":[[2023,7,7]]},"published-print":{"date-parts":[[2023,7]]},"abstract":"<jats:sec>\n                    <jats:title>Background<\/jats:title>\n                    <jats:p>Although decreased influenza activity has been reported in many countries during the COVID-19 pandemic, it remains unknown how global influenza activity has changed. We described the global variability of influenza activity and virus subtype circulation from 2011 to 2023 to prepare for the potential influenza outbreak with the control of the COVID-19 pandemic.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>Influenza virological surveillance data between 2011 and 2023 were obtained from the WHO-FluNet database. We first calculated and compared the influenza activity before and during the COVID-19 pandemic. For countries whose influenza activity has recovered, we also described changes in the duration of influenza epidemics. We then determined the proportion of influenza cases caused by the different influenza virus types.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>In total, 73 countries with 2.17\u2009million influenza cases were included. In the early stage of the COVID-19 pandemic, decreased influenza activity was observed in all WHO regions. In 2022 and 2023, rebound in influenza activity was observed in all WHO regions, especially in Western Pacific Region. At the same time, a change in the duration of the influenza epidemic was observed in several Southern Hemisphere countries. Moreover, in all WHO regions, few B\/Yamagata viruses were detected during the COVID-19 pandemic.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>Lack of exposure to influenza will diminish population immunity and increase the severity of large epidemics on a future global resurgence. Ongoing monitoring of the changes in the duration of the influenza epidemic and circulation subtypes should be the focus of future work.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjresp-2023-001638","type":"journal-article","created":{"date-parts":[[2023,7,25]],"date-time":"2023-07-25T13:02:50Z","timestamp":1690290170000},"page":"e001638","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":27,"title":["Global variability of influenza activity and virus subtype circulation from 2011 to 2023"],"prefix":"10.1136","volume":"10","author":[{"given":"Luyan","family":"Zheng","sequence":"first","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yushi","family":"Lin","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jing","family":"Yang","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kailu","family":"Fang","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jie","family":"Wu","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6159-9879","authenticated-orcid":false,"given":"Min","family":"Zheng","sequence":"additional","affiliation":[{"name":"State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, Zhejiang, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2023,7,25]]},"reference":[{"key":"2025083110503379000_10.1.e001638.1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(17)33293-2"},{"key":"2025083110503379000_10.1.e001638.2","doi-asserted-by":"crossref","first-page":"226","DOI":"10.1111\/irv.12699","article-title":"Passive immune therapy and other immunomodulatory agents for the treatment 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