Christopher Green is a Professor and Consultant Physician in Infectious Diseases & Global Health. As well as being a front-line NHS clinician, his main work and research interests focus on the development of new experimental vaccines for infectious diseases and in optimising vaccine impact in African settings. His DPhil at the University of Oxford was in leading the first-in-world clinical trials of viral-vectored vaccine technology for respiratory syncytial virus (RSV), which was directly relevant to COVID-19 vaccines needed to safely end the pandemic. He led many vaccine trials and other high-priority projects in this time and was a member of SAGE to UK government on hospital disease epidemiology. Today, his team works on clinical trials of experimental vaccines and is one of only a few global sites undertaking human challenge studies (deliberate infection) as part of an accelerated evaluation of vaccines for enteric fever. However, vaccine innovation needs to have impact. His global health research programmes are based in Rwanda, and this work includes (1) designing ‘next-generation’ vaccine deployment systems for equitable and sustainable vaccine policy implementation and future resilience to climate change and disease outbreaks, (2) the development of novel immune diagnostics for vaccine prioritisation, (3) clinical vaccine trials and (4) the development of ‘over the horizon’ public health threats detection systems.