Our group investigates how viral evolution shapes infection, immune escape and antiviral resistance. A central focus of the group is the genomic analysis of viral variants using next-generation sequencing. As part of the national German reference center for hepatitis C viruses (NRZ-HCV) we investigate the development of resistance mutations, improve diagnostics, and support public health responses by molecular surveillance. In cooperation with the AG Timm, we analyze how viral sequence variation influences T-cell responses and contributes to immune evasion in chronic infections such as hepatitis B and C. During the SARS-CoV-2 pandemic we could demonstrate that whole-genome sequencing can be integrated with epidemiological data to reconstruct transmission chains and support outbreak control. We are actively expanding Integrated Genomic Surveillance (IGS) to additional pathogens such as HCV and RSV, opening promising new avenues for disease control and public‑health impact.