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.

Huiberts, Anne J ORCID: 0000-0003-3206-9777, de Gier, Brechje, Hoeve, Christina E, de Melker, Hester E, Hahné, Susan JM, den Hartog, Gerco ORCID: 0000-0002-2103-6315, Grobbee, Diederick E, van de Wijgert, Janneke HHM ORCID: 0000-0003-2728-4560, van den Hof, Susan and Knol, Mirjam J (2023) 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. International journal of infectious diseases : IJID : official publication of the International Society for Infectious Diseases, 133. pp. 36-42.

Access the full-text of this item by clicking on the Open Access link.

Official URL: http://dx.doi.org/10.1016/j.ijid.2023.04.401

Abstract

<h4>Objectives</h4>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.<h4>Methods</h4>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.<h4>Results</h4>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.<h4>Conclusion</h4>Our results show the benefit of booster vaccinations against infection, also in risk groups; although, the additional protection wanes quite rapidly.

Item Type:	Article
Uncontrolled Keywords:	Humans, Vaccination, Prospective Studies, Adult, Middle Aged, Netherlands, COVID-19, SARS-CoV-2, COVID-19 Vaccines, Vaccine Efficacy
Divisions:	Faculty of Health and Life Sciences Faculty of Health and Life Sciences > Institute of Infection, Veterinary and Ecological Sciences
Depositing User:	Symplectic Admin
Date Deposited:	09 Apr 2024 10:16
Last Modified:	09 Apr 2024 14:08
DOI:	10.1016/j.ijid.2023.04.401
Open Access URL:	https://doi.org/10.1016/j.ijid.2023.04.401
Related URLs:	Author Publisher
URI:	https://livrepository.liverpool.ac.uk/id/eprint/3180228