Biological specimens
All biological specimens (faeces, blood, nasopharyngeal swabs, buccal swabs for DNA extraction, nasal swabs) will be coded and stored in the BioBank Maastricht UMC + and the UMCG for 10 years. These specimens will be used for the current trial and may be used for future research questions or analyses of new biomarkers. The data of the BioBank (such as the project number, respondent number, numbers, amount of samples available, and information about the quality) will be stored in a fully automatic web-based BioBank Information System (BIS).