Although studies of influenza in healthy volunteers have played an important role in addressing aspects of the natural history of influenza disease and developing novel antivirals, prior to recently these important studies had not been performed in the US in over a decade. The H1N1 challenge studies we have performed since 2012 have sought to improve upon the studies done in the past and address many of the limitations due to the scope of the studies and/or the scientific techniques available at that time. We have successfully developed an H1N1 model that had been used to address important questions regarding correlates of protection and is now being implemented to develop new drugs and vaccines. We hope to develop H3N2 models that can be just as useful.