2.4. Surveys
The online surveys allowed us to gather all the information on the health status and other important health-related parameters from trial participants. These surveys were provided to their parents and guardians through direct links sent via email, using the EU Survey tool [Three types of surveys were used in this trial were (1) initial, (2) daily and (3) weekly. Through the initial survey, we obtained the data needed for descriptive statistics and an overview of the characteristics of the trial participants. The daily surveys were the most important source of data for our experiment. Their questionnaire consisted of 6 questions, with the most important of them focusing on the participants’ health status, particularly inquiring about the severity of the URTI symptoms. Our weekly surveys served to enumerate days with any potential gastrointestinal side effects.The inquiry about the gravity of the URTIs symptoms was based on the following original scale, effectively introduced in our previous study, [