Ethical statement
The investigations were carried out in accordance with the General Data Protection Regulation (Regulation (EU) 2016/679 and Directive 95/46/EC) and the Finnish Personal Data Act (Finlex 523/1999) The Finnish Communicable Diseases Act (Finlex 1227/2016) allows sampling for diagnostic and surveillance purposes.
The convalescent serum sample was obtained on 14 February through informed consent of the patient and research permits (TYH2018322, TYH2019263) from the Helsinki University Hospital Laboratory.
Finnish population serum samples were collected during 2019. The study protocol was approved by the Ethics Committee of the Department of Medicine, Helsinki University Hospital (Permission 433/13/03/00/15).
Serum samples of University of Helsinki staff members were used under informed consent.