Low 2018/19 #vaccine #effectiveness against #influenza A(#H3N2) among 15–64-year-olds in #Europe: exploration by birth cohort (Euro Surveill., abstract)

[Source: Eurosurveillance, full page: (LINK). Abstract, edited.]

Low 2018/19 vaccine effectiveness against influenza A(H3N2) among 15–64-year-olds in Europe: exploration by birth cohort

Esther Kissling1, Francisco Pozo2, Silke Buda3, Ana-Maria Vilcu4, Alin Gherasim5,6, Mia Brytting7, Lisa Domegan8,9, Verónica Gómez10, Adam Meijer11, Mihaela Lazar12, Vesna Višekruna Vučina13, Ralf Dürrwald14, Sylvie van der Werf15,16, Amparo Larrauri5,6, Theresa Enkirch7, Joan O’Donnell8, Raquel Guiomar17, Mariëtte Hooiveld18, Goranka Petrović13, Elena Stoian12, Pasi Penttinen19, Marta Valenciano1, I-MOVE primary care study team20

Affiliations: 1 Epidemiology Department, Epiconcept, Paris, France; 2 National Centre for Microbiology, National Influenza Reference Laboratory, WHO-National Influenza Centre, Institute of Health Carlos III, Madrid, Spain; 3 Robert Koch Institute, Department of Infectious Disease Epidemiology, Respiratory Infections Unit, Berlin, Germany; 4 Sorbonne Université, INSERM, Institut Pierre Louis d’épidémiologie et de Santé Publique (IPLESP UMRS 1136), Paris, France; 5 National Epidemiology Centre, Institute of Health Carlos III, Madrid, Spain; 6 CIBER de Epidemiología y Salud Pública (CIBERESP), Institute of Health Carlos III, Madrid, Spain; 7 Public Health Agency of Sweden, Stockholm, Sweden; 8 Health Service Executive- Health Protection Surveillance Centre, Dublin, Ireland; 9 European Programme for Intervention Epidemiology Training (EPIET), European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden; 10 Departamento de Epidemiologia, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal; 11 National Institute for Public Health and the Environment (RIVM), Bilthoven, the Netherlands; 12 ”Cantacuzino” National Military-Medical Institute for Research and Development, Bucharest, Romania; 13 Croatian Institute of Public Health, Division for epidemiology of communicable diseases, Zagreb, Croatia; 14 Robert Koch Institute, National Reference Center for Influenza, Germany; 15 Unité de Génétique Moléculaire des Virus à ARN, Institut Pasteur, CNRS UMR3569, Université Paris Diderot SPC, France: 16 CNR des virus des infections respiratoires, WHO National Influenza Center, Institut Pasteur, Paris, France; 17 Departamento de Doenças Infeciosas, Instituto Nacional de Saúde Dr. Ricardo Jorge, Lisbon, Portugal; 18 Nivel (Netherlands Institute for Health Services Research), Utrecht, the Netherlands; 19 European Centre for Disease Prevention and Control (ECDC), Stockholm, Sweden; 20 The I-MOVE primary care study team members are listed at the end of the article

Correspondence:  Esther Kissling

Citation style for this article: Kissling Esther, Pozo Francisco, Buda Silke, Vilcu Ana-Maria, Gherasim Alin, Brytting Mia, Domegan Lisa, Gómez Verónica, Meijer Adam, Lazar Mihaela, Vučina Vesna Višekruna, Dürrwald Ralf, van der Werf Sylvie, Larrauri Amparo, Enkirch Theresa, O’Donnell Joan, Guiomar Raquel, Hooiveld Mariëtte, Petrović Goranka, Stoian Elena, Penttinen Pasi, Valenciano Marta, I-MOVE primary care study team. Low 2018/19 vaccine effectiveness against influenza A(H3N2) among 15–64-year-olds in Europe: exploration by birth cohort. Euro Surveill. 2019;24(48):pii=1900604. https://doi.org/10.2807/1560-7917.ES.2019.24.48.1900604

Received: 30 Sep 2019;   Accepted: 06 Nov 2019




Influenza A(H3N2) clades 3C.2a and 3C.3a co-circulated in Europe in 2018/19. Immunological imprinting by first childhood influenza infection may induce future birth cohort differences in vaccine effectiveness (VE).


The I-MOVE multicentre primary care test-negative study assessed 2018/19 influenza A(H3N2) VE by age and genetic subgroups to explore VE by birth cohort.


We measured VE against influenza A(H3N2) and (sub)clades. We stratified VE by usual age groups (0–14, 15–64, ≥ 65-years). To assess the imprint-regulated effect of vaccine (I-REV) hypothesis, we further stratified the middle-aged group, notably including 32–54-year-olds (1964–86) sharing potential childhood imprinting to serine at haemagglutinin position 159.


Influenza A(H3N2) VE among all ages was −1% (95% confidence interval (CI): −24 to 18) and 46% (95% CI: 8–68), −26% (95% CI: −66 to 4) and 20% (95% CI: −20 to 46) among 0–14, 15–64 and ≥ 65-year-olds, respectively. Among 15–64-year-olds, VE against clades 3C.2a1b and 3C.3a was 15% (95% CI: −34 to 50) and −74% (95% CI: −259 to 16), respectively. VE was −18% (95% CI: −140 to 41), −53% (95% CI: −131 to −2) and −12% (95% CI: −74 to 28) among 15–31-year-olds (1987–2003), 32–54-year-olds (1964–86) and 55–64-year-olds (1954–63), respectively.


The lowest 2018/19 influenza A(H3N2) VE was against clade 3C.3a and among those born 1964–86, corresponding to the I-REV hypothesis. The low influenza A(H3N2) VE in 15–64-year-olds and the public health impact of the I-REV hypothesis warrant further study.

©  This work is licensed under a Creative Commons Attribution 4.0 International License.

Keywords: Seasonal Influenza; H3N2; Vaccines; Original Antigenic Sin.


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Giuseppe Michieli

I am an Italian blogger, active since 2005 with main focus on emerging infectious diseases such as avian influenza, SARS, antibiotics resistance, and many other global Health issues. Other fields of interest are: climate change, global warming, geological and biological sciences. My activity consists mainly in collection and analysis of news, public services updates, confronting sources and making decision about what are the 'signals' of an impending crisis (an outbreak, for example). When a signal is detected, I follow traces during the entire course of an event. I started in 2005 my blog ''A TIME'S MEMORY'', now with more than 40,000 posts and 3 millions of web interactions. Subsequently I added an Italian Language blog, then discontinued because of very low traffic and interest. I contributed for seven years to a public forum (FluTrackers.com) in the midst of the Ebola epidemic in West Africa in 2014, I left the site to continue alone my data tracking job.