Received: 16 July 2020
Accepted: 28 October 2020
First Online: 11 November 2020
Ethical approval and consent to participate
: The study was approved by the Ethics Committee at Heim Pál National Pediatric Institute, Budapest (KUT-19/2019). Informed consent was obtained from all parents. All parents of the students included in the study received sufficient information.
: Not applicable.
: The authors report no conflicts of interest pertaining to the submitted work. AH is full time employee of Chiesi Hungary Ltd. GG reports personal fees from Astra-Zeneca, Chiesi, BMS, MSD, Berlin Chemie, Boehringer Ingelheim, Roche, Novartis, Pfizer, Ipsen, Mylen, Orion outside the submitted work.