Leo Visser is Head of the Department of Infectious Diseases (https://www.lumc.nl/org/infectieziekten/) and holds a position as Professor Infectious Disease, specifically travel medicine at the Leiden University Medical Centre in The Netherlands. He studied medicine at the Catholic University of Leuven in Belgium and graduated in 1985. He continued his medical training and was board certified for internal medicine in 1990 at the same University. He was registered as an infectious diseases specialist at Leiden University Medical Centre in 1992 and obtained his PhD at the Leiden University in 1997. Leo Visser is involved in clinical care, research and teaching in infectious diseases, with the emphasis on vaccine-preventable and tropical diseases, travel medicine and global health. He is head of the travel clinic, which is a centre for reference on travel medicine and vaccination in The Netherlands. He holds a professorship at University of Leiden and a lectureship at the Dutch National School of Public and Occupational Health. He is deputy director of the post-graduate training in internal medicine and director of the postgraduate training for infectious diseases at the Leiden University Medical Centre. Leo Visser is a member of the steering committee of TropNet (www.tropnet.eu) and president-elect of the International Society of Travel Medicine. His current research activities involve vaccination responses in immunocompromized hosts, immuneresponse to yellow fever vaccine; immunogenicity and safety of intradermally administered vaccines, and malaria vaccine research in collaboration with the University of Nijmegen.