tetano
Editor, Senior Moderator
Vaccine
. 2020 Nov 23;S0264-410X(20)31394-3.
doi: 10.1016/j.vaccine.2020.10.074. Online ahead of print.
Influenza vaccine effectiveness against laboratory-confirmed influenza in a vaccine-mismatched influenza B-dominant season
Y Drori[SUP] 1 [/SUP], R Pando[SUP] 2 [/SUP], H Sefty[SUP] 3 [/SUP], A Rosenberg[SUP] 3 [/SUP], E Mendelson[SUP] 4 [/SUP], L Keinan-Boker[SUP] 5 [/SUP], T Shohat[SUP] 6 [/SUP], M Mandelboim[SUP] 4 [/SUP], A Glatman-Freedman[SUP] 7 [/SUP], Israel Influenza Surveillance Network IISN
Affiliations
Abstract
Background: The 2017-2018 influenza season in Israel was characterized by the predominance of influenza B Yamagata, with a lesser circulation of influenza A(H1N1)pdm09 and influenza A(H3N2). We estimated vaccine effectiveness (VE) of the inactivated influenza vaccine which was selected for use that season.
Methods: End-of-season VE and 95% confidence intervals (CI) against laboratory-confirmed influenza-like illness (ILI) were estimated by means of the test-negative design. Age-specific VE analysis was carried out using a moving age interval.
Results: Specimen were obtained from 1,453 community ILI patients; 610 (42.0%) were influenza-positive, among which 69.7% were B, 17.2% A(H1N1)pdm09 and 13.4% A(H3N2). A 98.6% of molecularly characterized influenza B belonged to the Yamagata lineage. Of the sampled individuals, 1320 were suitable for VE analysis. Of those vaccinated, 90.6% received the inactivated trivalent influenza vaccine (TIV) containing a Victoria lineage influenza B-like virus. VE against influenza A differed by age, with the highest VE of 72.9% (95%CI 31.9-89.2%) observed in children 0.5-14 years old, while all ages VE was 46.6% (95%CI 10.4-68.2%). All ages VE against influenza B was 23.2% (95%CI -10.1-46.4%) with age-specific analysis showing non-significant VE estimates. Utilizing a moving age interval of 15 years, afforded a detailed age-specific insight into influenza VE against the influenza viruses circulating during the 2017-2018 season.
Conclusions: The moderate-high 2017-2018 influenza A VE among children and adolescents, supports seasonal influenza vaccination at a young age. The low VE against influenza B in Israel, is most likely the result of influenza B/TIV-mismatch.
Keywords: Influenza; Influenza vaccine; Vaccine effectiveness.
. 2020 Nov 23;S0264-410X(20)31394-3.
doi: 10.1016/j.vaccine.2020.10.074. Online ahead of print.
Influenza vaccine effectiveness against laboratory-confirmed influenza in a vaccine-mismatched influenza B-dominant season
Y Drori[SUP] 1 [/SUP], R Pando[SUP] 2 [/SUP], H Sefty[SUP] 3 [/SUP], A Rosenberg[SUP] 3 [/SUP], E Mendelson[SUP] 4 [/SUP], L Keinan-Boker[SUP] 5 [/SUP], T Shohat[SUP] 6 [/SUP], M Mandelboim[SUP] 4 [/SUP], A Glatman-Freedman[SUP] 7 [/SUP], Israel Influenza Surveillance Network IISN
Affiliations
- PMID: 33243633
- DOI: 10.1016/j.vaccine.2020.10.074
Abstract
Background: The 2017-2018 influenza season in Israel was characterized by the predominance of influenza B Yamagata, with a lesser circulation of influenza A(H1N1)pdm09 and influenza A(H3N2). We estimated vaccine effectiveness (VE) of the inactivated influenza vaccine which was selected for use that season.
Methods: End-of-season VE and 95% confidence intervals (CI) against laboratory-confirmed influenza-like illness (ILI) were estimated by means of the test-negative design. Age-specific VE analysis was carried out using a moving age interval.
Results: Specimen were obtained from 1,453 community ILI patients; 610 (42.0%) were influenza-positive, among which 69.7% were B, 17.2% A(H1N1)pdm09 and 13.4% A(H3N2). A 98.6% of molecularly characterized influenza B belonged to the Yamagata lineage. Of the sampled individuals, 1320 were suitable for VE analysis. Of those vaccinated, 90.6% received the inactivated trivalent influenza vaccine (TIV) containing a Victoria lineage influenza B-like virus. VE against influenza A differed by age, with the highest VE of 72.9% (95%CI 31.9-89.2%) observed in children 0.5-14 years old, while all ages VE was 46.6% (95%CI 10.4-68.2%). All ages VE against influenza B was 23.2% (95%CI -10.1-46.4%) with age-specific analysis showing non-significant VE estimates. Utilizing a moving age interval of 15 years, afforded a detailed age-specific insight into influenza VE against the influenza viruses circulating during the 2017-2018 season.
Conclusions: The moderate-high 2017-2018 influenza A VE among children and adolescents, supports seasonal influenza vaccination at a young age. The low VE against influenza B in Israel, is most likely the result of influenza B/TIV-mismatch.
Keywords: Influenza; Influenza vaccine; Vaccine effectiveness.