Mary is an Associate Professor in Global Studies of Science, Technology and Medicine, in the Department of History and Philosophy of Science, University of Cambridge. Her research interests lie broadly in historical intersections of science, technology, and medicine in China and around the world. Current projects include a study of the Sino-French Institute in Lyon, a collaborative exploration of the history of transportation technologies with particular consideration for transnational histories of civil aviation, and the early history of penicillin development in China.

Her 2019 book, Mass Vaccination: Citizens' Bodies and State Power in Modern China, examines the history of mass immunization in twentieth-century China. It suggests that the origins of the vaccination policies that eradicated smallpox and controlled other infectious diseases in the 1950s, providing an important basis for the emergence of Chinese health policy as a model for global health, can be traced to research and development in southwest China during the Second Sino-Japanese War.

She received her PhD in History from Yale and taught at Tufts University. In 2020, she received a CUSU Student-Led Teaching Prize in Partnership. Mary is a Fellow of Jesus College, an associate member of the World History Subject Group in the History Faculty, and a Trustee and Research Fellow of the Needham Research Institute.