1. Department of Dermatology, Venereology and Allergology, Saarland University Medical Center, D‑66421 Homburg, Germany
2. Department of Otorhinolaryngology, Head and Neck Surgery, Saarland University Medical Center, D‑66421 Homburg, Germany
3. Institute of Virology, Saarland University Medical Center, D‑66421 Homburg, Germany
4. Institute of Biometry, Epidemiology and Medical Informatics, Saarland University Medical Center, D‑66421 Homburg, Germany