Table 1.

Overview of stakeholder interaction activities that served as input for IMS diagram development. The numbers of the activities (1a to 7d) listed in this table appear in Figure 1.

Interaction type		Qualitative research method	Participants, location, timing	Main topics discussed
1	Exploration global level	Stakeholder interviews, conference workshops	1a MSF, Brussels 1b UNICEF, SC division, Copenhagen 1 c Vaccine manufacturers 1d Donor organisations 2015–2019	Links between Health system development and humanitarian aid, infrastructure gap, skills retention, project handover Vaccine funding, humanitarian mechanisms, vaccine stockpiles Health systems strengthening approach UNICEF, GAVI Improvement potential at interfaces of disciplines, e.g., vaccine manufacturing & procurement conditions, temperature requirements
2	Mental model elicitation national immunisation system	Group model building	Senior and middle EPI staff national level. Mixed groups: Kigali 2016: 22 participants from Rwanda, Kenya, Uganda, Tanzania, South-Sudan Nairobi 2017: 25 participants from Rwanda, Kenya, Uganda, Burundi, Tanzania, South-Sudan	Stakeholders involved in execution and decision making Mental model change from Supply Chain to systems thinking Policy making in cMYP, immunisation plan Private sector role and partnerships (logistics) Sharing views between countries, adapt approach to country Financial mechanisms, equity, sustainability, efficiency Data management and issues, denominator error Vaccine coverage and health outcomes: delays, epidemiology Implementation complexity: new vaccines, eLMIS Workforce capacity, immunisation integration in health services
3	Mental model elicitation district level	Interviews, observation, numerical data collection at DHs	Rwanda: 2 district hospitals (2018–2019) Kenya: 2 district hospitals (2018)	Vaccine supply chain, vaccine wastage, ordering process Outreach planning and funding Skills and training EPI staff and Community Health Workers Diversity between HCs in the district, root causes of coverage variation Demand data availability, district coordinating role
4	Mental model elicitation local level	Interviews, observations, numerical data collection at HCs, outreach, CHWs	Kenya: 5 health facilities (2018) Rwanda: 5 health facilities (2019)	Local vaccine management organisation, vaccine transport Community health worker, defaulter tracing, disease case detection Demand-side determinants, access to HFs Impact of local problem-solving capacity at HF
5	Validation national level IMS model	Feedback workshops	EPI, WHO, implementers Nairobi 2018, Kigali 2019	Data management Public-Private health services
6	Validation national level IMS model	Feedback meetings	EPI, Kigali, 2019 UNICEF, Kigali, 2019	Financial sustainability Supply chain redesign, Digital transformation Disease surveillance, emergency immunisation (measles, Ebola) Integration with other preventive HC systems (nutrition, Primary HC)
7	Validation and refinement by international domain experts	Feedback meetings (2019)	7a Academic anthropologist 7b Funding mechanism expert 7 c Academic Public Health 7d Academic systems expert	Vaccine hesitancy, emergency immunisation Design thinking, paradigm shift, Innovation interventions Sustainable mechanisms, Local contextual approach, community health Sustainability and resilient systems, systems levels and interventions