Influenza Vaccination in Italian Healthcare Workers (2018-2019 Season): Strengths and Weaknesses. Results of a Cohort Study in Two Large Italian Hospitals.
healthcare workers
influenza
influenza vaccination
influenza vaccination coverage
laboratory-confirmed influenza
Journal
Vaccines
ISSN: 2076-393X
Titre abrégé: Vaccines (Basel)
Pays: Switzerland
ID NLM: 101629355
Informations de publication
Date de publication:
05 Mar 2020
05 Mar 2020
Historique:
received:
31
01
2020
revised:
28
02
2020
accepted:
28
02
2020
entrez:
11
3
2020
pubmed:
11
3
2020
medline:
11
3
2020
Statut:
epublish
Résumé
Annual vaccination is the most effective way to combat influenza. As influenza viruses evolve, seasonal vaccines are updated annually. Within the European project Development of Robust and Innovative Vaccine Effectiveness (DRIVE), a cohort study involving Italian healthcare workers (HCWs) was carried out during the 2018-2019 season. Two aims were defined: to measure influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza cases and to conduct an awareness-raising campaign to increase vaccination coverage. Each subject enrolled was followed up from enrollment to the end of the study. Each HCW who developed ILI was swabbed for laboratory confirmation of influenza. Influenza viruses were identified by molecular assays. A Cox regression analysis, crude and adjusted for confounding variables, was performed to estimate the IVE. Among the 4483 HCWs enrolled, vaccination coverage was 32.5%, and 308 ILI cases were collected: 23.4% were positive for influenza (54.2% A(H1N1) pdm09; 45.8% A(H3N2)). No influenza B viruses were detected. No overall IVE was observed. Analyzing the subtypes of influenza A viruses, the IVE was estimated as 45% (95% CI: -59 to 81) for A(H1N1) pdm09. Vaccination coverage among HCWs increased. Study difficulties and the circulation of drifted variants of A(H3N2) could partly explain the observed IVE.
Sections du résumé
BACKGROUND
BACKGROUND
Annual vaccination is the most effective way to combat influenza. As influenza viruses evolve, seasonal vaccines are updated annually. Within the European project Development of Robust and Innovative Vaccine Effectiveness (DRIVE), a cohort study involving Italian healthcare workers (HCWs) was carried out during the 2018-2019 season. Two aims were defined: to measure influenza vaccine effectiveness (IVE) against laboratory-confirmed influenza cases and to conduct an awareness-raising campaign to increase vaccination coverage.
METHODS
METHODS
Each subject enrolled was followed up from enrollment to the end of the study. Each HCW who developed ILI was swabbed for laboratory confirmation of influenza. Influenza viruses were identified by molecular assays. A Cox regression analysis, crude and adjusted for confounding variables, was performed to estimate the IVE.
RESULTS
RESULTS
Among the 4483 HCWs enrolled, vaccination coverage was 32.5%, and 308 ILI cases were collected: 23.4% were positive for influenza (54.2% A(H1N1) pdm09; 45.8% A(H3N2)). No influenza B viruses were detected. No overall IVE was observed. Analyzing the subtypes of influenza A viruses, the IVE was estimated as 45% (95% CI: -59 to 81) for A(H1N1) pdm09.
CONCLUSIONS
CONCLUSIONS
Vaccination coverage among HCWs increased. Study difficulties and the circulation of drifted variants of A(H3N2) could partly explain the observed IVE.
Identifiants
pubmed: 32150801
pii: vaccines8010119
doi: 10.3390/vaccines8010119
pmc: PMC7157508
pii:
doi:
Types de publication
Journal Article
Langues
eng
Subventions
Organisme : DRIVE project - Innovative Medicines Initiative 2 Joint
ID : 777363
Références
PLoS One. 2019 Nov 14;14(11):e0225326
pubmed: 31725788
PLoS One. 2018 Jun 7;13(6):e0198685
pubmed: 29879206
BMC Health Serv Res. 2017 Nov 15;17(1):732
pubmed: 29141619
Euro Surveill. 2019 Nov;24(48):
pubmed: 31796152
Hum Vaccin. 2011 Jan-Feb;7 Suppl:217-25
pubmed: 21922688
BMC Pregnancy Childbirth. 2019 May 8;19(1):161
pubmed: 31068160
Acta Biomed. 2019 Sep 13;90(9-S):45-53
pubmed: 31517889
Expert Rev Vaccines. 2019 Jun;18(6):671-679
pubmed: 31159616
Public Health. 2018 Jan;154:102-109
pubmed: 29220709
Expert Rev Vaccines. 2020 Jan;19(1):115-122
pubmed: 31875483
MMWR Morb Mortal Wkly Rep. 2018 Feb 16;67(6):180-185
pubmed: 29447141
Vaccine. 2015 Jun 26;33(29):3276-80
pubmed: 25869892
Vaccine. 2017 Apr 4;35(15):1828-1843
pubmed: 28284681
Wkly Epidemiol Rec. 2018 Mar 23;93(12):133-41
pubmed: 29569429
Euro Surveill. 2013 Jan 31;18(5):
pubmed: 23399422
J Prev Med Hyg. 2019 Mar 29;60(1):E12-E17
pubmed: 31041405
Hum Vaccin Immunother. 2012 Jan;8(1):21-8
pubmed: 22252007
Euro Surveill. 2017 Mar 30;22(13):
pubmed: 28382917
Mol Biol Evol. 2013 Dec;30(12):2725-9
pubmed: 24132122
Euro Surveill. 2018 Feb;23(5):
pubmed: 29409570
Ann Ig. 2019 Jan-Feb;31(1):35-44
pubmed: 30554237
Euro Surveill. 2018 Apr;23(16):
pubmed: 29692315
Int J Mol Sci. 2019 May 30;20(11):
pubmed: 31151205
J Infect Dis. 2020 Jan 1;221(1):8-15
pubmed: 31665373
Hum Vaccin Immunother. 2015;11(1):95-100
pubmed: 25483521
Expert Rev Vaccines. 2019 Nov;18(11):1201-1209
pubmed: 31674847
Acta Biomed. 2019 Sep 13;90(9-S):21-27
pubmed: 31517886
Euro Surveill. 2017 Oct;22(43):
pubmed: 29090681
Euro Surveill. 2019 Feb;24(8):
pubmed: 30808440