Post-epidemic Health System Recovery: A Comparative Case Study Analysis of Routine Immunization Programs in the Republics of Haiti and Liberia

"As the world continues to navigate the COVID-19 pandemic,...[the] findings may be especially salient for health practitioners working to reverse population health setbacks and ensure the continuity of core public health programs like routine immunization."

Large-scale epidemics in resource-constrained settings disrupt delivery of core health services, such as routine immunisation. Two crises, the 2014-16 West Africa Ebola epidemic in Liberia and the 2010s cholera epidemic in Haiti, serve as instructive - and contrasting - cases of routine immunisation programme recovery after destabilising outbreaks. Though national coverage of the first dose of measles-containing vaccine (MCV1) plummeted to 58% in Liberia in 2014 (the first year of its Ebola epidemic), this estimate surged to 87% in 2017, the year after the epidemic was declared over. By contrast, national MCV1 coverage in Haiti stagnated between 64-69% during its years-long cholera epidemic (2010-2019), while the proportion of districts with MCV1 coverage above 80% fell to as low as 21.43% during this period. This study examines the factors that contributed to these differing trajectories, identifying facilitators and barriers of efforts to rebuild and strengthen routine immunisation programmes.

The researchers triangulated data between the peer-reviewed and grey literature, carried out in-depth key informant interviews with subject matter experts, and gathered quantitative metrics of population health and health system functioning. They used these data to construct thick descriptive narratives for each case and then performed a cross-case comparison.

The analysis shows that recovery efforts in Haiti were fragmented across a broad range of non-governmental agencies. Limitations in funding, workforce development, and community engagement further impeded vaccine uptake. Consequently, Haiti reported significant disparities in subnational immunisation coverage following the epidemic. One interviewee highlighted the logistical challenges associated with increasing routine coverage via campaigns, particularly as new vaccines were introduced into Haiti. Gavi also reported that a lack of proactive communication and messaging around the importance and value of vaccination - combined with poor patient experiences with healthcare providers - further undermined vaccine demand. Gavi further notes that forging public-private-civil society partnerships - for example, between the country's Expanded Programme on Immunization (EPI) programme, the Haitian Society of Pediatrics, the Haitian Red Cross, and the Haitian Platform for Civil Society Organisations to Strengthen Immunisation - could support improved immunisation outcomes in the future.

In contrast, post-Ebola routine immunisation coverage in Liberia surpassed pre-epidemic levels, a feat attributable to investments in surveillance, comprehensive risk communication, robust political support for and leadership around immunisation, and strong public-sector recovery planning. Rebuilding public trust in routine immunisation services, after Ebola, however - particularly among the hardest-hit populations - proved to be a challenge. Confronted with the task of scaling up trust across linguistic barriers, public health authorities coupled mass messaging approaches with grassroots strategies adapted to local contexts. One interviewee highlighted the role of the country's postwar peacebuilding infrastructure in supporting health communication, noting that it facilitated dialogue with chiefs in high-risk areas. Targeted demand generation and awareness-building strategies helped increase vaccine uptake. Activities included: establishing immunisation sites in marketplaces, where women with children often worked or shopped; enlisting town criers; broadcasting United Nations Children's Fund (UNICEF) radio programming; and coordinating social media campaigns in support of immunisation.

A matrix in the paper displays the findings from each case stacked side-by-side, organised within the Essential Public Health Services framework. This matrix is meant to facilitate comparison between the post-epidemic recovery experiences of Liberia and Haiti by disaggregating findings across relevant domains of health system functioning (i.e., assessment, policy development, and assurance). For example, the framework's policy development domain encompasses effective communication and health education, community mobilisation, policy formulation and implementation, and legal and regulatory measures to promote health. In Liberia, a combination of top-down and grassroots-level communication strategies - coupled with active outreach to last-mile communities - played an important role in recouping losses in routine immunisation coverage. By contrast, efforts to promote post-cholera routine immunisation in Haiti floundered; patient dissatisfaction with immunisation service quality at health facilities further diminished public demand for these services. Despite strong relationships with external donors and international organizations, Haiti also struggled to mobilise partnerships with domestic civil society groups well-poised to promote immunisation, such as the Haitian Red Cross. Like Haiti, Liberia also sustained strong relationships with international donors; in addition, it forged partnerships with community champions and civil society organisations, which proved consequential.

Despite differing trajectories of post-epidemic immunisation coverage, Haiti and Liberia share what is described here as a critical weakness: health workforce dissatisfaction. In addition, despite strong microplanning capacities, both countries reported major challenges in managing data, estimating immunisation coverage, and forecasting vaccine demand. Left unresolved, these shared challenges might hinder efforts to achieve and sustain high levels of routine immunisation coverage, as well as coordinate new vaccine introductions in the future.

In addition to the domains of the framework, the study identified several other similarities and differences between the two cases relating to the roles of colonialism in shaping health systems, the importance of country ownership and autonomy in matters of health governance, and the role of integration in facilitating post-epidemic recovery. For examle, as seen in both countries but particularly in Haiti, the implementation of vertical, donor-driven health initiatives in a vacuum of state capacity can undercut public trust in a government's ability to fulfill its social contract and, in some cases, may actually undermine efforts to develop, operationalise, and institutionalise knowledge, expertise, and capital within the public sector of the recipient country.

Insights from the study that may be transferrable to other resource-constrained settings include:

• Political leaders and domestic health authorities in affected countries should: conduct long-term planning to ensure alignment between budgets, plans, and routine immunisation programmes; treat routine immunisation and community health systems as critical national priorities worthy of sustained, long-term investment; strengthen linkages between various health system components; and improve compensation structures and working conditions for public-sector health workforces.
• Donors and other external stakeholders should strive to embed local expertise and leadership within vertical response and recovery structures, promote country ownership of domestic health programs, and work with in-country political leaders to support long-term budgetary and policy planning around routine immunisation, community health, and primary care.

To assess the confirmability of this investigation, researchers might wish to couple other methodological frameworks, such as a positive deviance lens, with additional forms of data (e.g., social media content, financial data, mobile data) and modes of data collection (e.g., focus groups, community-based participatory research, surveys) to gain insights into demand-side immunisation considerations. Future analyses might also compare perspectives across sectors and stakeholders to paint a more comprehensive picture of post-epidemic recovery. In addition, a formal power analysis of post-epidemic health system reforms could clarify how relationships between donors, policymakers, practitioners, and communities shape population health outcomes following major crises.

Thus, this study suggests that embedding in-country expertise within outbreak response structures, respecting governmental autonomy, aligning post-epidemic recovery plans and policies, and integrating outbreak response assets into robust systems of primary care can contribute to higher, more equitable levels of routine immunisation coverage in resource-constrained settings recovering from epidemics. How decision-makers and donors "coordinate both intra- and post-crisis recovery efforts will shape future trajectories of population health and health equity."