Repository logo

Browsing by Author "Humphreys, James"

Now showing 1 - 2 of 2
  • COVID-19 vaccine effectiveness in the paediatric population aged 5-17 years: a multicentre cohort study using electronic health registries in six European countries, 2021 to 2022
    Publication . Soares, Patricia; Machado, Ausenda; Nicolay, Nathalie; Monge, Susana; Sacco, Chiara; Hansen, Christian Holm; Meijerink, Hinta; Martínez-Baz, Iván; Schmitz, Susanne; Humphreys, James; Fabiani, Massimo; Echeverria, Aitziber; AlKerwi, Ala'a; Nardone, Anthony; Mateo-Urdiales, Alberto; Castilla, Jesús; Kissling, Esther; Nunes, Baltazar; VEBIS-Lot 4 working group
    Background: During the first year of the COVID-19 pandemic, vaccination programmes targeted children and adolescents to prevent severe outcomes of SARS-CoV-2 infection. Aim: To estimate COVID-19 vaccine effectiveness (VE) against hospitalisation due to COVID-19 in the paediatric population, among those with and without previously documented SARS-CoV-2 infection. Methods: We established a fixed cohort followed for 12 months in Denmark, Norway, Italy, Luxembourg, Navarre (Spain) and Portugal using routine electronic health registries. The study commenced with paediatric COVID-19 vaccination campaign at each site between June 2021 and January 2022. The outcome was hospitalisation with a laboratory-confirmed SARS-CoV-2 infection or COVID-19 as the main diagnosis. Using Cox proportional hazard models, VE was estimated as 1 minus the confounder-adjusted hazard ratio of COVID-19 hospitalisation between vaccinated and unvaccinated. A random-effects meta-analysis was used to pool VE estimates. Results: We included 4,144,667 5-11-year-olds and 3,861,841 12-17-year-olds. In 12-17-year-olds without previous infection, overall VE was 69% (95% CI: 40 to 84). VE declined with time since vaccination from 77% ≤ 3 months to 48% 180-365 days after immunisation. VE was 94% (95% CI: 90 to 96), 56% (95% CI: 3 to 80) and 41% (95% CI: -14 to 69) in the Delta, Omicron BA.1/BA.2 and BA.4/BA.5 periods, respectively. In 12-17-year-olds with previous infection, one dose VE was 80% (95% CI: 18 to 95). VE estimates were similar for 5-11-year-olds but with lower precision. Conclusion: Vaccines recommended for 5-17-year-olds provided protection against COVID-19 hospitalisation, regardless of a previously documented infection of SARS-CoV-2, with high levels of protection in the first 3 months of the vaccination.
    2025-02-27Journal article Open access Show more
  • 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: A VEBIS‐EHR Network Study
    Publication . Monge, Susana; Humphreys, James; Nicolay, Nathalie; Braeye, Toon; Van Evercooren, Izaak; Holm Hansen, Christian; Emborg, Hanne‐Dorthe; Sacco, Chiara; Mateo‐Urdiales, Alberto; Castilla, Jesús; Martínez‐Baz, Iván; de Gier, Brechje; Hahné, Susan; Meijerink, Hinta; Kristoffersen, Anja Bråthen; Machado, Ausenda; Soares, Patricia; Nardone, Anthony; Bacci, Sabrina; Kissling, Esther; Nunes, Baltazar
    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 booster-eligible ≥ 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-19 hospitalisation and death was, respectively, 67% (95%CI: 58–74) and 67% (95%CI: 42–81) in 65- to 79-year-olds and 66% (95%CI: 57–73) and 72% (95%CI: 51–85) in ≥ 80-year-olds. Results indicate that periodic vaccination of individuals ≥ 65 years has an ongoing benefit and support current vaccination strategies in the EU/EEA.
    2024-04-23Journal article Open access Show more