Dr Crellen is a parasitologist who uses genetic and epidemiological data to understand the distribution and evolutionary history of diseases including malaria, lymphatic filariasis, and schistosomiasis. He has had an impressive research career to date and has also spent time working as a field epidemiologist in D.R. Congo for Médecins Sans Frontieres. During the pandemic, he worked on mathematical models of coronavirus transmission and prepared and presented research for the Scientific Advisory Group for Emergencies (SAGE). He has conducted fieldwork in Central African Republic, Malawi, Kenya, Uganda, South Africa, Thailand, and D.R. Congo and is set to start as an Assistant Professor at the University of Singapore in 2025.