Received: 3 April 2020
Accepted: 16 June 2020
First Online: 23 June 2020
Ethics approval and consent to participate
: The study was approved by the Regional Ethics Committee in Uppsala, Sweden (2009/349). Written informed consent was obtained from each subject and from parents of subjects below 18 years of age, before inclusion in the study.
: Not applicable.
: JL, CJP and MPB are employed by ThermoFisher Scientific, Uppsala, Sweden. All other authors declare that they have no competing interests.