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Euro Surveill. 2018 Feb;23(7). doi: 10.2807/1560-7917.ES.2018.23.7.17-00026.
Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16.
Yaron-Yakoby H1, Sefty H2, Pando R3,2, Dichtiar R2, Katz MA4,5, Stein Y2, Mandelboim M3,1, Mendelson E3,1, Shohat T2,1, Glatman-Freedman A6,2,1, The Israeli Influenza Surveillance Network Iisn7.
Author information
Abstract
IntroductionInfluenza vaccine is recommended for the entire population in Israel. We assessed influenza vaccine effectiveness (VE) for the 2014/15 and 2015/16 seasons in Israel, for the first time. Methods: Combined nose and throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to sentinel primary care clinics and tested for influenza virus by RT-PCR. VE of the trivalent inactivated vaccine (TIV) was assessed using test-negative case-control design. Results: During the 2014/15 season 1,142 samples were collected; 327 (28.6%) were positive for influenza, 83.8% A(H3N2), 5.8% A(H1N1)pdm09, 9.2% B and 1.2% A un-subtyped. Adjusted VE against all influenza viruses for this influenza season was -4.8% (95% confidence interval (CI): -54.8 to 29.0) and against influenza A(H3N2), it was -15.8% (95% CI: -72.8 to 22.4). For the 2015/16 season, 1,919 samples were collected; 853 (44.4%) were positive for influenza, 43.5% A(H1N1)pdm09, 57% B, 0.7% A(H3N2) and 11 samples positive for both A(H1N1)pdm09 and B. Adjusted VE against all influenza viruses for this influenza season was 8.8% (95% CI: -25.1 to 33.5), against influenza A(H1N1)pdm09, it was 32.3% (95% CI: (-4.3 to 56.1) and against influenza B, it was -2.2% (95% CI: (-47.0 to 29.0). Conclusions: Using samples from patients with ILI visiting sentinel clinics in Israel, we demonstrated the feasibility of influenza VE estimation in Israel.
KEYWORDS:
ILI; immunisations; influenza; influenza-like illness; vaccines
PMID: 29471622 DOI: 10.2807/1560-7917.ES.2018.23.7.17-00026
Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16.
Yaron-Yakoby H1, Sefty H2, Pando R3,2, Dichtiar R2, Katz MA4,5, Stein Y2, Mandelboim M3,1, Mendelson E3,1, Shohat T2,1, Glatman-Freedman A6,2,1, The Israeli Influenza Surveillance Network Iisn7.
Author information
Abstract
IntroductionInfluenza vaccine is recommended for the entire population in Israel. We assessed influenza vaccine effectiveness (VE) for the 2014/15 and 2015/16 seasons in Israel, for the first time. Methods: Combined nose and throat swab specimens were collected from patients with influenza-like illness (ILI) presenting to sentinel primary care clinics and tested for influenza virus by RT-PCR. VE of the trivalent inactivated vaccine (TIV) was assessed using test-negative case-control design. Results: During the 2014/15 season 1,142 samples were collected; 327 (28.6%) were positive for influenza, 83.8% A(H3N2), 5.8% A(H1N1)pdm09, 9.2% B and 1.2% A un-subtyped. Adjusted VE against all influenza viruses for this influenza season was -4.8% (95% confidence interval (CI): -54.8 to 29.0) and against influenza A(H3N2), it was -15.8% (95% CI: -72.8 to 22.4). For the 2015/16 season, 1,919 samples were collected; 853 (44.4%) were positive for influenza, 43.5% A(H1N1)pdm09, 57% B, 0.7% A(H3N2) and 11 samples positive for both A(H1N1)pdm09 and B. Adjusted VE against all influenza viruses for this influenza season was 8.8% (95% CI: -25.1 to 33.5), against influenza A(H1N1)pdm09, it was 32.3% (95% CI: (-4.3 to 56.1) and against influenza B, it was -2.2% (95% CI: (-47.0 to 29.0). Conclusions: Using samples from patients with ILI visiting sentinel clinics in Israel, we demonstrated the feasibility of influenza VE estimation in Israel.
KEYWORDS:
ILI; immunisations; influenza; influenza-like illness; vaccines
PMID: 29471622 DOI: 10.2807/1560-7917.ES.2018.23.7.17-00026