- already received covid-19 vaccination - already had a positive test for covid-19 (this includes all types of tests, e.g. pcr tests or antibody tests) - allergy to an ingredient of the mini drinks - having donated blood within one month prior to the start of the study, or planning to donate blood during the study - pregnant women - breastfeeding women - excessive alcohol use (>20 consumptions per week) - regular use of soft or hard drugs

- already received covid-19 vaccination - already had a positive test for covid-19 (this includes all types of tests, e.g. pcr tests or antibody tests) - allergy to an ingredient of the mini drinks - having donated blood within one month prior to the start of the study, or planning to donate blood during the study - pregnant women - breastfeeding women - excessive alcohol use (>20 consumptions per week) - regular use of soft or hard drugs