Julien Vionnet, MD, PhD, PD, is a physician–scientist in transplantation medicine and immunology at Lausanne University Hospital (CHUV) and the University of Lausanne, Switzerland. He serves as Deputy Physician at the CHUV Centre for Organ Transplantation, where he has led the pre- and post-liver transplantation programme since 2012 in close collaboration with the Geneva University Hospitals within the Vaud–Geneva transplant network. He also leads the Transplantation Immunology Laboratory and Unit at CHUV, which provides advanced immune monitoring across solid-organ transplantation programmes.

Dr Vionnet obtained his PhD in Transplantation Immunology from King’s College London, where he trained as a clinical research fellow under the supervision of Professor Alberto Sanchez-Fueyo. His clinical and academic work focuses on liver transplantation, transplant immunology, biomarker-driven precision medicine, immunosuppression minimisation, and long-term outcomes after solid-organ transplantation. He has a particular interest in mechanisms of operational tolerance, donor-specific antibodies, donor-derived cell-free DNA, and cardiovascular risk in transplant recipients.

He is actively involved in national and international collaborative research, including projects within the Swiss Transplant Cohort Study, and regularly contributes to scientific peer review, education, and multidisciplinary transplant initiatives. As a clinician and investigator working at the interface of hepatology, transplantation, and immunology, he is committed to advancing personalised care and improving long-term outcomes for transplant recipients.

At ILTS 2026 in Geneva, Dr Vionnet is pleased to contribute as moderator and to support discussion on current challenges and future directions in liver transplantation.