1. Effectiveness of influenza vaccine in preventing medically-attended influenza virus infection in primary care, Israel, influenza seasons 2014/15 and 2015/16
- Author
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Tamy Shohat, Rakefet Pando, Ella Mendelson, Michal Mandelboim, Yaniv Stein, Aharona Glatman-Freedman, Hanna Sefty, Rita Dichtiar, Mark A. Katz, and Hamutal Yaron-Yakoby
- Subjects
0301 basic medicine ,Male ,Epidemiology ,0302 clinical medicine ,Influenza A Virus, H1N1 Subtype ,030212 general & internal medicine ,Israel ,Child ,Nose ,Aged, 80 and over ,Reverse Transcriptase Polymerase Chain Reaction ,Vaccination ,virus diseases ,vaccines ,Middle Aged ,Throat swab ,medicine.anatomical_structure ,Influenza Vaccines ,Child, Preschool ,Female ,Seasons ,influenza ,Research Article ,Adult ,medicine.medical_specialty ,Adolescent ,Influenza vaccine ,030106 microbiology ,influenza-like illness ,Primary care ,Virus ,03 medical and health sciences ,Virology ,Internal medicine ,Influenza, Human ,medicine ,Humans ,immunisations ,Vaccine Potency ,Aged ,Influenza-like illness ,Primary Health Care ,business.industry ,Influenza A Virus, H3N2 Subtype ,Public Health, Environmental and Occupational Health ,Infant ,Confidence interval ,Case-Control Studies ,Inactivated vaccine ,ILI ,business ,Sentinel Surveillance - Abstract
Introduction Influenza 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.
- Published
- 2018