I have developed analytical decision-support models for a range of vaccines, including Haemophilus influenzae type b (Hib), pneumococcal, rotavirus, human papillomavirus (HPV), and respiratory syncytial virus (RSV) vaccines. The models provide a framework for stakeholder engagement, capacity strengthening, and national ownership of results. The models have been used to support decision-making by national immunisation technical advisory groups in more than 40 low- and middle-income countries (LMICs) and have also informed global World Health Organization (WHO) guidelines e.g. the policy to relax rotavirus vaccine age restrictions in high mortality settings (Clark et al, Lancet Global Health 2019). My research also involves generating the empirical evidence that underpins these models e.g. quantifying the extent to which children in LMICs experience delays in receiving various vaccines (Clark et al, Lancet Global Health 2026; Clark and Sanderson, Lancet 2009), estimating age distributions for different respiratory syncytial virus disease outcomes (Mahmud, van Zandvoort...Clark, Lancet Child & Adolescent Health 2026), quantifying the number of people at increased risk of severe COVID-19 disease due to chronic conditions (Clark et al, Lancet Global Health 2020), and estimating the efficacy of live oral rotavirus vaccines in different mortality settings (Clark et al, Lancet Infectious Diseases 2019).

I am particularly interested in models that are able to realistically capture individual-level variation in vaccination protection and disease risk. MSc and PhD/DrPH students with an interest in this topic are welcome to contact me.