- commitment not to use any products that may influence the study outcome (e.g. immune suppressants/immune stimulants, including paramedication such as e.g. Echinacea, analgesics/anti-rheumatics, anti-phlogistics, antitussives/expectorants, influenza remedies, mouth or throat therapeutics, decongestants, antibiotics, anti-histaminergic drugs, probiotics) during the study (except for rescue medication, see 7.5)