The Duke Human Vaccine Institute (DHVI) serves as one of two clinical cores for the CIVICs program. The DHVI has a longstanding history of leading numerous seasonal, pandemic, universal, and special population influenza vaccine studies and collaborating on many human challenge studies. Investigators within the Duke CIVICs Clinical Core conduct clinical trials and human challenge studies for promising influenza vaccines, vaccine components, and vaccine delivery systems developed by the Vaccine Centers and other external collaborators. Clinical trials include Phase I studies in healthy adults and Phase I/II studies in populations at risk of more severe influenza, including older adults, children, and pregnant women. Human influenza challenge studies are conducted in healthy adults. Duke leads the effort to harmonize the endpoint assays used to evaluate clinical trials and human challenge studies, including correlates of protection and durable immunity. The Clinical Core also manages the biorepository of samples obtained from the clinical trials and challenge studies to enable future research.  Collectively, the Core helps advance safe and promising improvements and innovations in influenza vaccine design through the clinical pipeline.