Samuel Alizon is a theoretical biologist who uses concepts and tools from evolutionary biology and ecology to study questions revolving around health. His research focuses in particular on human viruses (HPV, HIV, HCV, or SARS-Cov-2).

After a thesis aimed at understanding why parasites harm their hosts using mathematical models, he worked as an adjunct assistant professor at Queen's University in Kingston (Canada) and as an ETH fellow in Zürich (Switzerland), where he studied the virulence of the human immunodeficiency virus (HIV). In 2010 he was hired as a CNRS research fellow at the MIVEGEC laboratory in Montpellier, and then promoted to Research Director in 2017. In collaboration with colleagues at the Montpellier University Hospital, he conducted clinical research projects, including the PAPCLEAR study aimed at better understanding the ecology of papillomavirus (HPV) infections in young women. Since mid-March 2020, his team has been analyzing and modeling the COVID-19 epidemic in France. He is the author of numerous research articles and of a popularison book in French (Évolution, écologie et pandémies, published by Points/Seuil in 2020).