tetano
Editor, Senior Moderator
J Infect Dis
. 2023 Jan 23;jiad015.
doi: 10.1093/infdis/jiad015. Online ahead of print.
Vaccine effectiveness against influenza-associated urgent care, emergency department, and hospital encounters during the 2021-2022 season, VISION Network
Mark W Tenforde[SUP] 1 [/SUP], Zachary A Weber[SUP] 2 [/SUP], Malini B DeSilva[SUP] 3 [/SUP], Edward Stenehjem[SUP] 4 [/SUP], Duck-Hye Yang[SUP] 2 [/SUP], Bruce Fireman[SUP] 5 [/SUP], Manjusha Gaglani[SUP] 6 7 [/SUP], Noah Kojima[SUP] 1 [/SUP], Stephanie A Irving[SUP] 8 [/SUP], Suchitra Rao[SUP] 9 [/SUP], Shaun J Grannis[SUP] 10 11 [/SUP], Allison L Naleway[SUP] 8 [/SUP], Lindsey Kirshner[SUP] 2 [/SUP], Anupam B Kharbanda[SUP] 12 [/SUP], Kristin Dascomb[SUP] 4 [/SUP], Ned Lewis[SUP] 5 [/SUP], Alexandra F Dalton[SUP] 1 [/SUP], Sarah W Ball[SUP] 2 [/SUP], Karthik Natarajan[SUP] 13 14 [/SUP], Toan C Ong[SUP] 9 [/SUP], Emily Hartmann[SUP] 15 [/SUP], Peter J Embi[SUP] 10 16 [/SUP], Charlene E McEvoy[SUP] 3 [/SUP], Nancy Grisel[SUP] 4 [/SUP], Ousseny Zerbo[SUP] 5 [/SUP], Margaret M Dunne[SUP] 2 [/SUP], Julie Arndorfer[SUP] 4 [/SUP], Kristin Goddard[SUP] 5 [/SUP], Monica Dickerson[SUP] 1 [/SUP], Palak Patel[SUP] 1 [/SUP], Julius Timbol[SUP] 5 [/SUP], Eric P Griggs[SUP] 1 [/SUP], John Hansen[SUP] 5 [/SUP], Mark G Thompson[SUP] 1 [/SUP], Brendan Flannery[SUP] 1 [/SUP], Nicola P Klein[SUP] 5 [/SUP]
Affiliations
Abstract
Background: Following historically low influenza activity during the 2020-2021 season, the United States saw an increase in influenza circulating during the 2021-2022 season. Most viruses belonged to the influenza A(H3N2) 3C.2a1b 2a.2 subclade.
Methods: We conducted a test-negative case-control analysis among adults ≥18 years of age at three sites within the VISION Network. Encounters included emergency department/urgent care (ED/UC) visits or hospitalizations with ≥1 acute respiratory illness (ARI) discharge diagnosis codes and molecular testing for influenza. Vaccine effectiveness (VE) was calculated by comparing the odds of influenza vaccination ≥14 days before the encounter date between influenza-positive cases (type A) and influenza-negative and SARS-CoV-2-negative controls, applying inverse probability-to-be-vaccinated weights, and adjusting for confounders.
Results: 86,732 ED/UC ARI-associated encounters (7,696 [9%] cases) and 16,805 hospitalized ARI-associated encounters (649 [4%] cases) were included. VE against influenza-associated ED/UC encounters was 25% (95% confidence interval (CI): 20-29%) and 25% (95%CI: 11-37%) against influenza-associated hospitalizations. VE against ED/UC encounters was lower in adults ≥65 years of age (7%; CI: -5-17%) or with immunocompromising conditions (4%, CI:-45-36%).
Conclusions: During an influenza A(H3N2)-predominant influenza season, modest VE was observed. These findings highlight the need for improved vaccines, particularly for A(H3N2) viruses that are historically associated with lower VE.
Keywords: COVID-19; bias; influenza; test-negative design; vaccine effectiveness.
. 2023 Jan 23;jiad015.
doi: 10.1093/infdis/jiad015. Online ahead of print.
Vaccine effectiveness against influenza-associated urgent care, emergency department, and hospital encounters during the 2021-2022 season, VISION Network
Mark W Tenforde[SUP] 1 [/SUP], Zachary A Weber[SUP] 2 [/SUP], Malini B DeSilva[SUP] 3 [/SUP], Edward Stenehjem[SUP] 4 [/SUP], Duck-Hye Yang[SUP] 2 [/SUP], Bruce Fireman[SUP] 5 [/SUP], Manjusha Gaglani[SUP] 6 7 [/SUP], Noah Kojima[SUP] 1 [/SUP], Stephanie A Irving[SUP] 8 [/SUP], Suchitra Rao[SUP] 9 [/SUP], Shaun J Grannis[SUP] 10 11 [/SUP], Allison L Naleway[SUP] 8 [/SUP], Lindsey Kirshner[SUP] 2 [/SUP], Anupam B Kharbanda[SUP] 12 [/SUP], Kristin Dascomb[SUP] 4 [/SUP], Ned Lewis[SUP] 5 [/SUP], Alexandra F Dalton[SUP] 1 [/SUP], Sarah W Ball[SUP] 2 [/SUP], Karthik Natarajan[SUP] 13 14 [/SUP], Toan C Ong[SUP] 9 [/SUP], Emily Hartmann[SUP] 15 [/SUP], Peter J Embi[SUP] 10 16 [/SUP], Charlene E McEvoy[SUP] 3 [/SUP], Nancy Grisel[SUP] 4 [/SUP], Ousseny Zerbo[SUP] 5 [/SUP], Margaret M Dunne[SUP] 2 [/SUP], Julie Arndorfer[SUP] 4 [/SUP], Kristin Goddard[SUP] 5 [/SUP], Monica Dickerson[SUP] 1 [/SUP], Palak Patel[SUP] 1 [/SUP], Julius Timbol[SUP] 5 [/SUP], Eric P Griggs[SUP] 1 [/SUP], John Hansen[SUP] 5 [/SUP], Mark G Thompson[SUP] 1 [/SUP], Brendan Flannery[SUP] 1 [/SUP], Nicola P Klein[SUP] 5 [/SUP]
Affiliations
- PMID: 36683410
- DOI: 10.1093/infdis/jiad015
Abstract
Background: Following historically low influenza activity during the 2020-2021 season, the United States saw an increase in influenza circulating during the 2021-2022 season. Most viruses belonged to the influenza A(H3N2) 3C.2a1b 2a.2 subclade.
Methods: We conducted a test-negative case-control analysis among adults ≥18 years of age at three sites within the VISION Network. Encounters included emergency department/urgent care (ED/UC) visits or hospitalizations with ≥1 acute respiratory illness (ARI) discharge diagnosis codes and molecular testing for influenza. Vaccine effectiveness (VE) was calculated by comparing the odds of influenza vaccination ≥14 days before the encounter date between influenza-positive cases (type A) and influenza-negative and SARS-CoV-2-negative controls, applying inverse probability-to-be-vaccinated weights, and adjusting for confounders.
Results: 86,732 ED/UC ARI-associated encounters (7,696 [9%] cases) and 16,805 hospitalized ARI-associated encounters (649 [4%] cases) were included. VE against influenza-associated ED/UC encounters was 25% (95% confidence interval (CI): 20-29%) and 25% (95%CI: 11-37%) against influenza-associated hospitalizations. VE against ED/UC encounters was lower in adults ≥65 years of age (7%; CI: -5-17%) or with immunocompromising conditions (4%, CI:-45-36%).
Conclusions: During an influenza A(H3N2)-predominant influenza season, modest VE was observed. These findings highlight the need for improved vaccines, particularly for A(H3N2) viruses that are historically associated with lower VE.
Keywords: COVID-19; bias; influenza; test-negative design; vaccine effectiveness.