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Multicenter Study
. 2023 Jan;17(1):e13069.
doi: 10.1111/irv.13069. Epub 2022 Nov 21.

Influenza vaccine effectiveness against influenza A subtypes in Europe: Results from the 2021-2022 I-MOVE primary care multicentre study

Esther Kissling  1 , Francisco Pozo  2   3 , Iván Martínez-Baz  3   4 , Silke Buda  5 , Ana-Maria Vilcu  6 , Lisa Domegan  7 , Clara Mazagatos  3   8 , Frederika Dijkstra  9 , Neus Latorre-Margalef  10 , Sanja Kurečić Filipović  11 , Ausenda Machado  12 , Mihaela Lazar  13 , Itziar Casado  3   4 , Ralf Dürrwald  5 , Sylvie van der Werf  14   15 , Joan O'Donnell  7 , Juan Antonio Linares Dopido  16 , Adam Meijer  9 , Maximilian Riess  10 , Vesna Višekruna Vučina  11 , Ana Paula Rodrigues  12 , Maria Elena Mihai  13 , Jesús Castilla  3   4 , Luise Goerlitz  5 , Alessandra Falchi  17 , Jeff Connell  18 , Daniel Castrillejo  19 , Mariette Hooiveld  20 , Annasara Carnahan  10 , Maja Ilić  11 , Raquel Guiomar  12 , Alina Ivanciuc  13 , Marine Maurel  1 , Ajibola Omokanye  21 , Marta Valenciano  1 ; I-MOVE study team
Affiliations
Multicenter Study

Influenza vaccine effectiveness against influenza A subtypes in Europe: Results from the 2021-2022 I-MOVE primary care multicentre study

Esther Kissling et al. Influenza Other Respir Viruses. 2023 Jan.

Abstract

Background: In 2021-2022, influenza A viruses dominated in Europe. The I-MOVE primary care network conducted a multicentre test-negative study to measure influenza vaccine effectiveness (VE).

Methods: Primary care practitioners collected information on patients presenting with acute respiratory infection. Cases were influenza A(H3N2) or A(H1N1)pdm09 RT-PCR positive, and controls were influenza virus negative. We calculated VE using logistic regression, adjusting for study site, age, sex, onset date, and presence of chronic conditions.

Results: Between week 40 2021 and week 20 2022, we included over 11 000 patients of whom 253 and 1595 were positive for influenza A(H1N1)pdm09 and A(H3N2), respectively. Overall VE against influenza A(H1N1)pdm09 was 75% (95% CI: 43-89) and 81% (95% CI: 45-93) among those aged 15-64 years. Overall VE against influenza A(H3N2) was 29% (95% CI: 12-42) and 25% (95% CI: -41 to 61), 33% (95% CI: 14-49), and 26% (95% CI: -22 to 55) among those aged 0-14, 15-64, and over 65 years, respectively. The A(H3N2) VE among the influenza vaccination target group was 20% (95% CI: -6 to 39). All 53 sequenced A(H1N1)pdm09 viruses belonged to clade 6B.1A.5a.1. Among 410 sequenced influenza A(H3N2) viruses, all but eight belonged to clade 3C.2a1b.2a.2.

Discussion: Despite antigenic mismatch between vaccine and circulating strains for influenza A(H3N2) and A(H1N1)pdm09, 2021-2022 VE estimates against circulating influenza A(H1N1)pdm09 were the highest within the I-MOVE network since the 2009 influenza pandemic. VE against A(H3N2) was lower than A(H1N1)pdm09, but at least one in five individuals vaccinated against influenza were protected against presentation to primary care with laboratory-confirmed influenza.

Keywords: Europe; influenza; influenza vaccine; multicentre study; vaccine effectiveness.

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Conflict of interest statement

All authors declare no conflict of interest.

Figures

FIGURE 1
FIGURE 1
Number of ILI/ARI reports by case status, week of symptom onset, and number of SARS‐CoV‐2 cases among influenza‐negative controls, I‐MOVE primary care multicentre case control study, 2021–2022 influenza season
FIGURE 2
FIGURE 2
All influenza (upper figure, in blue) and influenza A(H3N2) (lower figure, in red) vaccine effectiveness by days since vaccination. I‐MOVE primary care multicentre case control study, influenza season 2021–2022
See this image and copyright information in PMC

References

    1. Kissling E, Valenciano M, Buchholz U, et al. Influenza vaccine effectiveness estimates in Europe in a season with three influenza type/subtypes circulating: the I‐MOVE multicentre case‐control study, influenza season 2012/13. Euro Surveill. 2014;19(6):20701. doi: 10.2807/1560-7917.ES2014.19.6.20701 - DOI - PubMed
    1. Kissling E, Valenciano M, Pozo F, et al. 2015/16 I‐MOVE/I‐MOVE+ multicentre case‐control study in Europe: moderate vaccine effectiveness estimates against influenza A(H1N1)pdm09 and low estimates against lineage‐mismatched influenza B among children. Influenza Other Respi Viruses. 2018;12(4):423‐437. doi: 10.1111/irv.12520 - DOI - PMC - PubMed
    1. Kissling E, Valenciano M, Cohen JM, et al. I‐MOVE multi‐centre case control study 2010–11: overall and stratified estimates of influenza vaccine effectiveness in Europe. PLoS ONE. 2011;6(11):e27622. doi: 10.1371/journal.pone.0027622 - DOI - PMC - PubMed
    1. Valenciano M, Kissling E, Cohen JM, et al. Estimates of pandemic influenza vaccine effectiveness in Europe, 2009–2010: results of Influenza Monitoring Vaccine Effectiveness in Europe (I‐MOVE) multicentre case‐control study. PLoS Med. 2011;8(1):e1000388. doi: 10.1371/journal.pmed.1000388 - DOI - PMC - PubMed
    1. Kissling E, Valenciano M, Falcão JM, et al. ‘I‐MOVE’ towards monitoring seasonal and pandemic influenza vaccine effectiveness: lessons learnt from a pilot multi‐centric case‐control study in Europe, 2008‐9. Euro Surveill. 2009;14(44):19388. doi: 10.2807/ese.14.44.19388-en - DOI - PubMed

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