Health System Strengthening (HSS) is essential for vaccination coverage. Global, national and regional vaccination initiatives are increasingly attentive to HSS in achieving sustainable health improvement. However, ambiguity remains as to what is meant by HSS at different levels of the health systems, different policy contexts and at the interfaces of global and national level debates. In global health initiatives the question is how to reconcile disease-specific targets and the need for overarching HSS t o achieve long-term health improvement.The project provides an ethnographic perspective on the interface of HSS and vaccination policies and programmes and is a collaborative effort between researchers from SUM- Centre of Environment and Development at t he University of Oslo, London School of Hygiene and Tropical Medicine and Public Health Foundation of India. The project conceptualise the vaccination field as a transnational coalition of diverse organisational types competing for resources and influence and propose a deliberative and interpretive approach to policy analysis. Such an approach takes into account actors' understandings, values and beliefs as expressed through language and behaviour. Specifically, the project examines how diverse actors wit hin the field of vaccination research, policy and programmes understand and pursue HSS, as well as the politics, power dynamics and key debates that shape the interactions between global institutions, bilateral donors and national and state actors. The us e of scientific and operational evidence to elaborate HSS strategies within vaccination initiatives will be examined. The National Rural Health Mission of India provides a case study to explore local and state challenges of HSS within national vaccination programmes. The project will provide knowledge on how vaccination policy can contribute to HSS and catalyse overall health improvement, including global goals for child and maternal health and survival