1. Department of Otorhinolaryngology, Plastic, Aesthetic and Reconstructive Head and Neck Surgery, University of Wuerzburg, D‑97080 Wuerzburg, Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery, Kepler University Hospital, A‑4021 Linz, Austria
3. Institute for Virology and Immunobiology, University of Wuerzburg, D‑97080 Wuerzburg, Germany
4. Department of Otorhinolaryngology, Head and Neck Surgery ‘Otto K�rner’, University Medical Center Rostock, D‑18057 Rostock, Germany