Funding for this research was provided by:
Province of Styria [Land Steiermark] (n.a.)
Received: 29 May 2019
Accepted: 20 January 2020
First Online: 4 February 2020
Ethics approval and consent to participate
: The study was approved by the local Ethical Committee of the Medical University of Graz (EC-Nr. 30–263 ex 17/18).
: Patient’s data is retrospectively reported in anonymous form. No informed consent was necessary.
: WZ received financial support for organizing the „Graz vaccination day “from GSK, Pfizer, Merck, and Sanofi. The remaining authors have no conflicts of interests.