Effectiveness of XBB.1.5 monovalent COVID-19 vaccines during a period of
XBB.1.5 dominance in EU/EEA countries, October to November 2023
Abstract
Using a common protocol across seven countries in the European
Union/European Economic Area, we estimated XBB.1.5 monovalent vaccine
effectiveness (VE) against COVID-19 hospitalisation and death in
≥65-year-olds, during October-November 2023. We linked electronic
records to construct retrospective cohorts and used Cox models to
estimate adjusted Hazard Ratios and derive VE. VE for COVID-10
hospitalisation and death was, respectively, 67% (95%CI: 60-72) and
68% (95%CI: 44-82) in 65–79-year-olds, and 64% (95%CI: 49-75) and
74% (95%CI: 56-85) in ≥80-year-olds. Results indicate that periodic
vaccination of individuals ≥65 years has an ongoing benefit, and support
the current vaccination strategies in the EU/EEA.