Funding for this research was provided by:
Governmental grants provided to the Public Health Agency of Sweden (S2020/0281/FS, S2020/08532 FS)
Received: 5 January 2022
Accepted: 20 June 2022
First Online: 25 June 2022
: JWB and MF are shareholders of Xerum AB that performed the serological analyses. All other authors declare that there is no conflict of interest.