Klaus is currently Dean of the Jockey Club College of Veterinary Medicine and Life Sciences at City University. He previously served as Professor of Virology and Chair at Freie Universität Berlin, Germany (2007 – 2020), and Adjunct Professor of Virology at Cornell University (2007 – present). After finishing his veterinary degree in 1990, Klaus entered the field of virology, initially working with poxviruses. After his dissertation in 1993, his scientific focus switched to herpesviruses, specifically to work with equine herpesvirus type 1 (EHV-1). He completed his “Habilitation“ in 1997. In the same year, Klaus started to work as a group leader at the Friedrich-Loeffler-Institute in Insel Riems, and began his investigations of an oncogenic herpesvirus, Marek’s disease virus (MDV) of chickens. He has continued to work on these two herpesviruses during his time on the faculty at Cornell and in Berlin. More recently his research extended into influenza and coronaviruses (SARS- and MERS-CoV, infectious bronchitis virus of chickens, and canine coronaviruses).
Klaus is an avid advocate of using natural virus-host systems, because of their unique model character and because they allow harnessing the strength of collaboration with clinicians and researchers from other disciplines. Using infectious clones and reverse genetics, his laboratory mechanistically studies viral pathogenesis and utilizes this knowledge for engineering of modified live virus vaccines. His research has been funded continuously since 1994 by public funding agencies including the European Union, the NIH, the USDA, the DFG and other public sources. He has also secured support for his work from pharmaceutical companies and philanthropists. Klaus has more than 230 scientific publications and his h-index currently stands at 51. He is editor and member of the editorial board of a number of journals, and his honors include membership in the Academy of Sciences of Thuringia since 2014, the Young Investigator Award of the Academy for Animal Health (2002) and the WVPA-Boehringer Ingelheim Vaccine Innovation Award (2017).
Blocking of viruses at the portal of entry is an extremely attractive approach to combat infections and for pandemic preparedness. We have explored various strategies for the inhibition of viruses at mucosal surfaces, particularly in the oronasal cavity. Our work has focused on carbon-based architectures, especially graphene and its derivatives. One of the major problems in the development of novel virus inhibitor systems is the adaption of the inhibitor to the size of virus particles, and we synthesized and tested carbon-based inhibitors of different sizes to evaluate potential size effects on the inhibition of virus entry and replication. Nanomaterials were functionalized with polygylcerol through a "grafting from" polymerization to form new polyvalent nanoarchitectures, which allowed polysulfation to mimic the heparan sulfates present on cell surfaces that we reasoned would compete with the binding sites of herpes viruses. Inhibitory efficiency is regulated by the size of the polymeric nanomaterials and the degree of sulfation and the derivatives inhibited virus infection at an early stage as predicted. In similar work, inhibition of SARS-CoV-2 by graphene platforms with precise dual sulfate/alkyl functionalities was investigated. A series of graphene derivatives with different lengths of aliphatic chains were synthesized and we showed that graphene derivatives with long alkyl chains (>C9) inhibit coronavirus replication by virtue of disrupting viral envelope.