Effectiveness of Influenza Vaccine in Preventing Medically-Attended Influenza Virus Infection in Primary Care, Israel, Influenza Seasons 2014/15 and 2015/16

Authors

Hamutal Yaron-Yakoby
Hanna Sefty
Rakefet PandoFollow
Rita Dichtiar
Mark A. Katz
Aharona Glatman-Freedman, New York Medical CollegeFollow
The Israeli Influenza Surveillance Network (IISN)

DOI

10.2807/1560-7917.ES.2018.23.7.17-00026

Journal Title

Euro Surveillance

First Page

17-00026

Document Type

Article

Publication Date

2-1-2018

Department

Pediatrics

Keywords

Influenza Vaccines, Influenza, Human, Israel, Outcome Assessment (Health Care), Vaccine Potency

Disciplines

Medicine and Health Sciences

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.

Comments

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Recommended Citation

Yaron-Yakoby, H., Sefty, H., Pando, R., Dichtiar, R., Katz, M., Glatman-Freedman, A., & The Israeli Influenza Surveillance Network (IISN). (2018). Effectiveness of Influenza Vaccine in Preventing Medically-Attended Influenza Virus Infection in Primary Care, Israel, Influenza Seasons 2014/15 and 2015/16. Euro Surveillance, 23 (7), 17-00026. https://doi.org/10.2807/1560-7917.ES.2018.23.7.17-00026

Publisher's Statement

Originally published in Euro Surveillance, 23(7) [Article 17-00026]. The original material can be found here.

Creative Commons License

This work is licensed under a Creative Commons Attribution 4.0 International License.