Chris Bonell is Professor of Public Health Sociology and Associate Dean for Research at the London School of Hygiene and Topical Medicine, previously been a professor at University College London and Oxford University. He specialises in adolescent health, sexual health and the evaluation of public health interventions. He co-directed the evaluation of the Learning Together whole-school health intervention which reported effectiveness across multiple health outcomes. He is currently leading the evaluation of the Positive Choices relations and sex education intervention. He advises the UK government and the World Health Organisation on COVID19 prevention and in particular the role of schools.