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. 2019 Sep 13;90(9-S):21-27.
doi: 10.23750/abm.v90i9-S.8699.

On field vaccine effectiveness in three periods of 2018/2019 influenza season in Emilia-Romagna Region

Maria Eugenia Colucci  1 , Licia Veronesi, Maria Teresa Bracchi, Roberta Zoni, Luca Caruso, Emanuela Capobianco, Deanna Rossi, Assunta Bizzarro, Angelo Cantarelli, Paola Affanni
Affiliations

On field vaccine effectiveness in three periods of 2018/2019 influenza season in Emilia-Romagna Region

Maria Eugenia Colucci et al. Acta Biomed. .

Abstract

Background and aim of the work: Epidemic influenza is associated with significant morbidity and mortality, particularly in people at risk. The vaccine reduces complications, hospitalization and mortality excess, as well as health care and social costs. Aim of the study was to estimate the influenza vaccine effectiveness (VE) in Emilia-Romagna Region during the 2018/2019 season.

Methods: Within the context of virological surveillance conducted at the Regional Reference Laboratory of Parma, nasal/throat swabs were performed by sentinel practitioners and clinicians, on patients with ILI (Influenza-like illness). VE estimates, overall and against subtype A(H1N1)pdm09 and A(H3N2), were evaluated in three periods of the season, using a test-negative case-control design.

Results: From November 2018 to April 2019, 2,230 specimens were analyzed: 1,674 (75.1%) performed by clinicians and 556 (24.9%) by sentinel practitioners of the regional network. The season was characterized by the predominant circulation of influenza type A viruses: 57.4% belonged to subtype A(H3N2), 41.2% to subtype A(H1N1)pdm09. 23.5% of patients was vaccinated against influenza with quadrivalent or adjuvate vaccine. The overall VE was -5% (95% CI -33% - 18%) with a decreasing trend during the season. The overall VE against subtype A(H1N1)pdm09 was 39% (95% CI 11% - 58%) and remained stable during the season. The overall VE against subtype A(H3N2) was -43% (95% CI -89% - -9%), and showed an important decreasing trend.

Conclusions: The possibility to make accurate and continuous VE estimates during the season will help to better define the composition of the vaccine for the following season.

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Conflict of interest statement

Each author declares that he or she has no commercial associations (e.g. consultancies, stock ownership, equity interest, patent/licensing arrangement etc.) that might pose a conflict of interest in connection with the submitted article

Figures

Figure 1.
Figure 1.
Number of swabs and specimens positive for influenza virus by hospital Care Unit
Figure 2.
Figure 2.
Number of specimens positive for influenza virus, by type or subtype and week of specimen collection
Figure 3.
Figure 3.
Adjusted estimates of Influenza Vaccine Effectiveness (VE) against virus type or subtype, overall and stratified according to epidemic period
See this image and copyright information in PMC

References

    1. World Health Organization (WHO) Global Influenza Programme. A Manual for Estimating Disease Burden Associated With Seasonal Influenza. Sept 2015
    1. European Center for Disease Control (ECDC) Influenza remains a threat. Available from: https://ecdc.europa.eu/en/seasonal-influenza/facts/key-messages) (last accessed on 12 June 2019)
    1. Smetana J, Chlibek R, Shaw J, Splino M, Prymula R. Influenza vaccination in the elderly. Hum Vaccin Immunother. 2018 Mar 4;14(3):540–549. - PMC - PubMed
    1. Circolare n.9/2018. Prevenzione e controllo dell’influenza. Raccomandazioni per la stagione 2018/2019. Available from: http://salute.regione.emilia-romagna.it/documentazione/materiale-informa... .
    1. CDC. Estimated influenza illnesses, medical visits, and hospitalizations averted by vaccination. Available from: https://www.cdc.gov/flu/about/disease/burden-averted-vaccination.htm. (last accessed on 12 June 2019)

MeSH terms

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