tetano
Editor, Senior Moderator
- Esther Kissling[SUP]1,2,*[/SUP]
, Marine Maurel[SUP]1,*[/SUP] , Francisco Pozo[SUP]3,4[/SUP] , Gloria Pérez-Gimeno[SUP]4,5[/SUP] , Silke Buda[SUP]6[/SUP] , Noémie Sève[SUP]7[/SUP] , Lisa Domegan[SUP]8[/SUP] , Mariëtte Hooiveld[SUP]9[/SUP] , Beatrix Oroszi[SUP]10[/SUP] , Iván Martínez-Baz[SUP]4,11[/SUP] , Raquel Guiomar[SUP]12[/SUP] , Neus Latorre-Margalef[SUP]13[/SUP] , Ivan Mlinarić[SUP]14[/SUP] , Mihaela Lazar[SUP]15[/SUP] , Jaume Giménez Duran[SUP]16[/SUP] , Ralf Dürrwald[SUP]6[/SUP] , Vincent Enouf[SUP]17[/SUP] , Adele McKenna[SUP]8[/SUP] , Marit de Lange[SUP]18[/SUP] , Gergő Túri[SUP]10[/SUP] , Camino Trobajo-Sanmartín[SUP]4,11[/SUP] , Verónica Gomez[SUP]19[/SUP] , Tove Samuelsson Hagey[SUP]13[/SUP] , Vesna Višekruna Vučina[SUP]14[/SUP] , Maria Carmen Cherciu[SUP]15[/SUP] , Miriam García Vazquez[SUP]20[/SUP] , Annika Erdwiens[SUP]6[/SUP] , Shirley Masse[SUP]21[/SUP] , Charlene Bennett[SUP]22[/SUP] , Adam Meijer[SUP]18[/SUP] , Katalin Kristóf[SUP]23[/SUP] , Jesús Castilla[SUP]4,11[/SUP] , Ana Paula Rodrigues[SUP]19[/SUP] , Sanja Kurečić Filipović[SUP]14[/SUP] , Alina Elena Ivanciuc[SUP]15[/SUP] , Sabrina Bacci[SUP]24[/SUP] , Marlena Kaczmarek[SUP]24[/SUP] , on behalf of the European primary care VE group[SUP]25[/SUP]
Influenza A(H1N1)pdm09, A(H3N2) and B/Victoria viruses circulated in Europe in 2023/24, with A(H1N1)pdm09 dominance. First influenza infections in childhood may lead to different vaccine effectiveness (VE) in subsequent years.
Aim
The VEBIS primary care network estimated influenza VE in Europe using a multicentre test‐negative study.
Methods
Primary care practitioners collected information and specimens from patients consulting with acute respiratory infection. We estimated VE against influenza (sub)type and clade, by age group and by year of age for A(H1N1)pdm09, using logistic regression.
Results
We included 29,958 patients, with 3,054, 1,053 and 311 influenza A(H1N1)pdm09, A(H3N2) and B cases, respectively. All-age VE against influenza A(H1N1)pdm09 was 52% (95% CI: 44–59). By year of age, VE was 27% (95% CI: −2 to 47) at 44 years with peaks at 72% (95% CI: 52–84) and 54% (95% CI: 41–64) among children and those 65 years and older, respectively. All-age A(H1N1)pdm09 VE against clade 5a.2a was 41% (95% CI: 24–54) and −11% (95% CI: −69 to 26) against clade 5a.2a.1. The A(H3N2) VE was 35% (95% CI: 20–48) among all ages and ranged between 34% and 40% by age group. All-age VE against clade 2a.3a.1 was 38% (95% CI: 1–62). All-age VE against B/Victoria was 83% (95% CI: 65–94), ranging between 70 and 92% by age group.
Discussion
The 2023/24 VEBIS primary care VE against medically attended symptomatic influenza infection was high against influenza B/Victoria, but lower against influenza A(H1N1)pdm09 and A(H3N2). Clade- and age-specific effects may have played a role in the lower A(H1N1)pdm09 VE.
https://www.eurosurveillance.org/content/10.2807/1560-7917.ES.2025.30.23.2500011