Fig. 1

Study design with number of study participants, vaccine and sampling timepoints, and the different dominant SARS-CoV-2 variant periods. (a) Information on the number of COVID-19 confirmed cases and deaths of older adults aged 70 years or over who live in a nursing home in the Netherlands. Data was collected until the 11th of July 2023 and obtained from data.rivm.nl/covid-19/. Additionally, information on vaccine dose administration, sampling timepoints, and circulating SARS-CoV-2 variants of concern have been indicated in the graph. (b) A flowchart depicting vaccine dose administration and sampling timepoints together with information on the number of study participants per timepoint