1 Institute of Virology, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany.
2 Department I of Internal Medicine, Faculty of Medicine and University Hospital Cologne, University of Cologne, Cologne, Germany; German Center for Infection Research, partner site Bonn-Cologne, Cologne, Germany; Center for Molecular Medicine Cologne, University of Cologne, Cologne, Germany. Electronic address: philipp.schommers@uk-koeln.de.