Vaccine effectiveness of primary and booster COVID-19 vaccinations against SARS-CoV-2 infection in the Netherlands from July 12, 2021 to June 6, 2022: A prospective cohort study
Objectives: We estimated vaccine effectiveness (VE) of primary and booster vaccinations against SARS-CoV-2 infection overall and in four risk groups defined by age and medical risk condition during the Delta and Omicron BA.1/BA.2 periods. Methods: VAccine Study COvid-19 is an ongoing prospective cohort study among Dutch adults. The primary end point was a self-reported positive SARS-CoV-2 test from July 12, 2021 to June 06, 2022. The analyses included only participants without a previous SARS-CoV-2 infection based on a positive test or serology. We used Cox proportional hazard models with vacc... Mehr ...
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Dokumenttyp: | Artikel |
Erscheinungsdatum: | 2023 |
Reihe/Periodikum: | International Journal of Infectious Diseases, Vol 133, Iss , Pp 36-42 (2023) |
Verlag/Hrsg.: |
Elsevier
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Schlagwörter: | COVID-19 / SARS-CoV-2 / Vaccine effectiveness / Infectious and parasitic diseases / RC109-216 |
Sprache: | Englisch |
Permalink: | https://search.fid-benelux.de/Record/base-28760933 |
Datenquelle: | BASE; Originalkatalog |
Powered By: | BASE |
Link(s) : | https://doi.org/10.1016/j.ijid.2023.04.401 |
Objectives: We estimated vaccine effectiveness (VE) of primary and booster vaccinations against SARS-CoV-2 infection overall and in four risk groups defined by age and medical risk condition during the Delta and Omicron BA.1/BA.2 periods. Methods: VAccine Study COvid-19 is an ongoing prospective cohort study among Dutch adults. The primary end point was a self-reported positive SARS-CoV-2 test from July 12, 2021 to June 06, 2022. The analyses included only participants without a previous SARS-CoV-2 infection based on a positive test or serology. We used Cox proportional hazard models with vaccination status as the time-varying exposure and adjustment for age, sex, educational level, and medical risk condition. Results: A total of 37,170 participants (mean age 57 years) were included. In the Delta period, VE <6 weeks after the primary vaccination was 80% (95% confidence interval 69-87) and decreased to 71% (65-77) after 6 months. VE increased to 96% (86-99) shortly after the first booster vaccination. In the Omicron period, these estimates were 46% (22-63), 25% (8-39), and 57% (52-62), respectively. For the Omicron period, an interaction term between vaccination status and risk group significantly improved the model (P <0.001), with generally lower VEs for those with a medical risk condition. Conclusion: Our results show the benefit of booster vaccinations against infection, also in risk groups; although, the additional protection wanes quite rapidly.