Influenza Vaccine Effectiveness in the United States During the 2016–2017 Season. (11th September 2018)

• Record Type: Journal Article
• Authors: Flannery, Brendan; Chung, Jessie R; Monto, Arnold S; Martin, Emily T; Belongia, Edward A; McLean, Huong Q; Gaglani, Manjusha; Murthy, Kempapura; Zimmerman, Richard K; Nowalk, Mary Patricia; Jackson, Michael L; Jackson, Lisa A; Rolfes, Melissa A; Spencer, Sarah; Fry, Alicia M
• Is Part Of: Clinical infectious diseases. Volume 68:Number 11(2019)
• Page Start: 1798
• Page End: 1806
• Publication Date: 2018-09-11
• Subjects: influenza vaccine -- vaccine effectiveness; Communicable diseases -- Periodicals; 616.905
• DOI: 10.1093/cid/ciy775
• Languages: English
• ISSNs: 1058-4838

Abstract

Abstract: Background: In recent influenza seasons, the effectiveness of inactivated influenza vaccines against circulating A(H3N2) virus has been lower than against A(H1N1)pdm09 and B viruses, even when circulating viruses remained antigenically similar to vaccine components. Methods: During the 2016–2017 influenza season, vaccine effectiveness (VE) across age groups and vaccine types was examined among outpatients with acute respiratory illness at 5 US sites using a test-negative design that compared the odds of vaccination among reverse transcription polymerase chain reaction–confirmed influenza positives and negatives. Results: Among 7083 enrollees, 1342 (19%) tested positive for influenza A(H3N2), 648 (9%) were positive for influenza B (including B/Yamagata, n = 577), and 5040 (71%) were influenza negative. Vaccine effectiveness was 40% (95% confidence interval [CI], 32% to 46%) against any influenza virus, 33% (95% CI, 23% to 41%) against influenza A(H3N2) viruses, and 53% (95% CI, 43% to 61%) against influenza B viruses. Conclusions: The 2016–2017 influenza vaccines provided moderate protection against any influenza among outpatients but were less protective against influenza A(H3N2) viruses than B viruses. Approaches to improving effectiveness against A(H3N2) viruses are needed. Abstract : The 2016–2017 influenza vaccines provided moderate protection against any influenza among outpatients but were less protective against influenza A(H3N2) viruses than B viruses.