Identifying Vulnerabilities in Essential Health Services: Analysing the Effects of System Shocks on Childhood Vaccination Delivery in Lebanon

"Considering the polio outbreak in the neighbourhood countries, it was not possible for the Lebanese Ministry and for the sector also and the humanitarian agencies to wait until all these refugees settle and know where are the primary healthcare centres and go for their vaccines. It was very important for us to mobilise for the vaccination activities to go and reach them [with] door-to-door vaccination activities in order to prevent any major outbreaks and to help the system withstand all this pressure."

Lebanon has experienced a series of shocks in recent years, including large-scale refugee arrivals from neighbouring Syria, the COVID-19 pandemic, and a political-economic crisis. Using qualitative system dynamics, this study explored how effects of multiple shocks interacted across system levels and combined with existing vulnerabilities to produce effects on essential health services delivery, through the prism of a case study on childhood vaccination in Lebanon. The focus was on better understanding how successive shocks affected activities at multiple levels (from national down to facility-level) to create within-system risks to vaccination delivery, and how and where these shocks interacted in their effects within the system.

The researchers applied qualitative system dynamics (SD) modelling, a methodological approach that generates visualisations - called causal loop diagrams (CLDs) - of cause-and-effect relationships within a system underpinning behaviour over time. They developed a CLD to explore the effects of each shock individually, and in combination. The CLD was developed and validated using qualitative data from interviews with 38 stakeholders working in Lebanon's vaccination delivery system, in roles ranging from national level policy to facility-level service delivery, conducted between February 2020 and January 2022.

In the high-level CLD (see figure 3 in the paper), stable elements of the supply and demand sides of the vaccination delivery system are represented in blue, feeding into the primary outcome (vaccination uptake); dynamics linked to the various shocks are highlighted in red (population displacement), purple (the COVID-19 pandemic), and brown (the economic crisis) respectively. In this visualisation, "availability of consumables" describes access to necessary elements for vaccine administration; "demand mobilisation activities" refers to the combination of communication activities and engagement work carried out to drive up vaccine uptake.

In brief, the study found that each of the shocks had different effects on service demand- and supply-side dynamics. These effects cascaded from national through to local levels. Both Syrian refugee movement and the COVID-19 pandemic primarily exposed vulnerabilities in service demand, mainly through slowly emerging knock-on effects on vaccination uptake behaviour among host communities and fear of contracting infection in crowded health facilities, respectively. For example:
 

• Several interviewees highlighted vulnerabilities created by the re-allocation of Ministry of Public Health resources to the pandemic response and away from vaccine-preventable disease (VPD) case surveillance. They highlighted that without adequate surveillance, there was a risk that response work using community engagement to increase demand for vaccination in areas where new cases had been identified would not be triggered in a timely way.
• The economic crisis exposed wider system vulnerabilities, including demand for vaccination as household income collapsed, and supply-side effects such as reduced clinic time for vaccination, declining workforce retention, and reduced availability of viable vaccine doses, among others.

Finally, pathways of interaction between shocks were identified, particularly affecting the balance between demand for vaccination through publicly supported facilities and private clinics. For instance, refugee arrivals from Syria gradually drove an increase in demand for vaccination, but this took time to emerge. As it did so, rising primary healthcare centre attendances contributed to facility-level crowding, and in some cases clinic closures, as demand outstripped the capacity health workers perceived they had to administer vaccines. This situation reduced uptake, especially among host communities. 

Findings from this study underscore the importance of sufficient human resourcing at multiple system levels to sustain vaccination delivery irrespective of the shock. The study also demonstrated how demand-side dynamics influence system resilience, but also the extent to which effects differ according to the nature and intensity of the shock. Effects were most pronounced during COVID-19 (where risk perception conditioned vaccine uptake behaviour) and especially during the economic crisis, as worsening conditions appeared to downgrade the perceived importance of vaccination relative to other immediate priorities for many households.

According to the researchers, future research should consider both the generalisability of these to other service areas and contexts, and consider intervention approaches that might meaningfully address vulnerabilities in the interests of long-term system resilience.