Franz X. Heinz distinguished himself above all through his work in the field of flaviviruses, with research into tick-borne encephalitis (FSME) virus occupying a central position in his scientific work. He played a key role in the development of the TBE vaccine and the elucidation of the atomic structure of the viral surface glycoprotein, which is responsible for inducing protective immunity. In addition, he made important contributions to the elucidation of the mechanism of viral membrane fusion, the laboratory diagnostics of flavivirus infections, the epidemiology of the TBE virus and the molecular antigen structure of flaviviruses.