Mourning for founding and honorary member Professor Harald zur Hausen

Society of Virology mourns the loss of its founding and honorary member, Nobel Prize winner Professor Dr. med. Harald zur Hausen. He was a pioneer in the field of cancer-causing viruses, discovered the link between infections with human papillomaviruses and cervical cancer and thus laid the foundation for vaccination against these pathogens. He was awarded the Nobel Prize for Medicine or Physiology in 2008 for his groundbreaking work.

Harald zur Hausen studied medicine in Bonn, Hamburg and finally in Düsseldorf, where he received his doctorate in 1960. After working as a medical assistant in Wimbern, Isny and his birthplace of Gelsenkirchen, he obtained his license to practice medicine in 1962 and then worked as a research assistant at the Institute for Hygiene and Microbiology at the University of Düsseldorf until 1966.

Already fascinated at this time by the possibility of an infectious cause of certain cancers, Harald zur Hausen began a research stay in 1966 in the Division of Virology at the Children's Hospital of Philadelphia, in the laboratory of Gertrude and Werner Henle. At that time, the research couple had discovered a connection between the Epstein-Barr virus (EBV) and Burkitt's lymphoma, which is why Harald zur Hausen also worked on this topic during his stay in the Henle laboratory. His particular focus in these and subsequent years was on the molecular biological detection of viral nucleic acids in tumor cells, even if they did not produce viruses or viral proteins. He was particularly interested in the question of how viruses can influence human chromosomes and genes, a topic that would not let him go. In 1968, Harald zur Hausen was appointed Assistant Professor of Virology at the University of Pennsylvania. He held this position until his return to Germany in 1969, where he joined Eberhard Wecker's Institute of Virology at the Julius Maximilian University of Würzburg. There he habilitated in virology with a series of original papers, which primarily dealt with the possible connection between herpes viruses and adenoviruses and certain human tumors. He was unable to detect any herpesviral DNA in cervical tumors, although the prevailing opinion at the time was that these viruses were associated with the development of this type of tumor.

In 1972, Harald zur Hausen was appointed professor at the newly founded Institute of Clinical Virology at the University of Erlangen-Nuremberg. As part of his work on genital warts and cervical tumors, he travelled to Kenya in 1976 to collect biopsies. He had the biopsies analyzed individually and found evidence that there are different papilloma viruses. Certain of these viruses, he suggested, could be linked to cervical cancer, a hypothesis that was widely rejected and in some cases discredited at the time. In 1977, Harald zur Hausen was appointed to the Chair of Virology and Hygiene at the Centre for Hygiene at the University of Freiburg, where he and his research group confirmed the causal link between certain papillomaviruses and genital tumours over the following years; during this time, types 16 and 18, which are responsible for >70% of cervical cancer cases, were identified and characterized. This laid the foundation for the development of corresponding vaccines.

From 1983 to 2003, Harald zur Hausen was Chairman and Scientific Member of the Board of Trustees of the German Cancer Research Center in Heidelberg. He found himself in a difficult situation there after a review had warned of an inadequate scientific position, particularly in international competition. He personally visited and assessed the groups at the DKFZ and thus gained a picture of the situation; as a result, on the basis of scientific evaluations, there was a clear structural and content-related change and reorientation, which brought the DKFZ into the top league of corresponding research institutes. This also affected Funding the early independence of young scientists, many of whom subsequently took up leading positions in other research institutions. His conviction that basic research was an important prerequisite for medical progress shaped the future direction of the DKFZ to a great extent. He combined this conviction with the central concern of transferring the results of basic research into clinical application. In collaboration with Heidelberg University Hospital, this led to the establishment of clinical cooperation units and ultimately to the founding of the National Center for Tumor Diseases in Heidelberg. Harald zur Hausen maintained his interest in experimental work and visited his laboratory almost daily to discuss the very latest results. Over the course of time, the research focus "Applied Tumor Virology" (now called "Infection, Inflammation & Cancer") was consistently built up under the direction of Harald zur Hausen in order to be able to investigate the topic of human papillomaviruses and cancer in all its facets. It is no exaggeration to say that Harald zur Hausen, in his 20 years as Chairman of the DKFZ Foundation Board, has made this institution an international leader in the field of cancer research.

After his retirement in 2003, Harald zur Hausen was awarded the Nobel Prize for Medicine in 2008 "for his discovery of human papilloma viruses causing cervical cancer", according to the official citation of the Nobel Committee in Stockholm. He has also received a large number of other highly prestigious prizes and awards, including the Robert Koch Prize (1975), the German Cancer Prize (1986), the Paul Ehrlich and Ludwig Darmstaedter Prize (1994), the Ernst Jung Prize and the Jacob Henle Medal (1996), the Prince Mahidol Prize (2005), the LoefflerFrosch Medal of Society of Virology (2007), the Johann Georg Zimmermann Medal (2007) and the Gairdner Foundation International Award (2008). He also received the Grand Cross of the Order of Merit of the Federal Republic of Germany with Star for his numerous achievements, which was presented to him by the then Federal President Horst Köhler in 2009. Furthermore, Harald zur Hausen has received more than 30 honorary doctorates and honorary professorships.

Harald zur Hausen is rightly regarded as a pioneer in the field of cancer-causing viruses. His work has had a significant impact on this topic and he has defended and ultimately proven his thesis on the link between human papillomaviruses and cervical cancer with great energy and against much opposition. This persistence is often described as "Westphalian stubbornness" and was certainly a decisive factor in the success of his work. His assumption has now been proven by numerous other research groups. Nobody doubts it anymore and his findings have found their way into textbooks. Harald zur Hausen's work laid the foundation for the development of a vaccine to prevent infection with the relevant oncogenic papillomaviruses. Thanks to his perseverance, two such vaccines were approved for clinical use in 2006; their effectiveness in preventing cervical cancer has now been clearly proven. This can undoubtedly be regarded as a milestone in cancer prevention. Harald zur Hausen has not only carried out ground-breaking basic research, but has also consistently translated this into clinical application.

As a person, Harald zur Hausen was greatly appreciated for his friendly, reserved and objective manner. He always had good advice for budding scientists. We still remember one of them in particular: "You should always assume that most of the hypotheses you put forward are wrong and must either be corrected or rejected." This requires a certain tolerance for frustration, but that is part of being a scientist. But it is also a learning process, because the assumption that scientific statements are irrefutable, even in scientific publications, is not correct. Science is highly dynamic, a realization that many of us and the general public have had to learn, especially during the pandemic. Unfortunately, Harald zur Hausen will no longer be at our side with his important advice. We will sorely miss him and keep him in lasting memory.

Ralf Bartenschlager and Hans-Georg Kräusslich

In recognition of his life and scientific achievements, we would like to draw your attention to the interview with Prof. Harald zur Hausen, which was published in the April 2022 newsletter of jGfV .