Background: Scarce European data in early 2021 suggested lower vaccine effectiveness (VE) against SARS-CoV-2 Omicron lineages than previous variants. Aim: We aimed to estimate primary series (PS) and first booster VE against symptomatic BA.1/BA.2 infection and investigate potential biases. Methods: This European test-negative multicentre study tested primary care patients with acute respiratory symptoms for SAR...
Background: Influenza A(H3N2) viruses dominated early in the 2022-2023 influenza season in Europe, followed by higher circulation of influenza A(H1N1)pdm09 and B viruses. The VEBIS primary care network estimated the influenza vaccine effectiveness (VE) using a multicentre test-negative study. Materials and methods: Primary care practitioners collected information and specimens from patients consulting with acut...
Background: The 2018/2019 influenza season in the WHO European Region was dominated by influenza A (H1N1)pdm09 and (H3N2) viruses, with very few influenza B viruses detected. Methods: Countries in the European Region reported virus characterization data to The European Surveillance System for weeks 40/2018 to 20/2019. These virus antigenic and genetic characterization and haemagglutinin (HA) sequence data were ...