Mark Jit is a mathematical modeller at the Health Protection Agency, United Kingdom, where he leads work around modelling and economic evaluation of vaccine-preventable diseases. He is also an honorary senior lecturer at the Health Economics Unit of the University of Birmingham. His work has helped to influence policy making around rotavirus, human papillomavirus, pneumococcal and influenza vaccination in the UK and around the world. In particular, his collaborative work around influenza modelling with colleagues in public health and academia helped to inform vaccination policy during the 2009 pandemic, as well as seasonal influenza vaccination policy after 2009. He has received a BSc in Mathematics at University College London, a PhD in mathematical modelling of biological systems at the same university, and a Master of Public Health at Kings College London.