Guest editorial: Vaccine supply in perspective: from end-to-end supply chains to full-fledged immunization systems

[...]in an End-To-End approach (De Boeck et al., 2019;Lemmens et al., 2016), multiple aspects of the supply network need to be considered and coordinated, in a way that many upstream decisions and aspects in R&D have a considerable impact on the downstream supply network up to the very last mile and point of vaccination. The next paper "Enhancing the Environmental Sustainability of Emergency Humanitarian Medical Cold Chains with Renewable Energy Sources” by Saari extends toward sustainability by focusing on the cold chain aspects of vaccine supply chains. [...]the seventh and closing paper "Modeling a closed-loop vaccine supply chain with transshipments to minimize wastage and threats to the public: a system dynamics approach”, by Andiç-Mortan and Gonul Kochan, shows by means of a causal loop diagram causal relationships with respect to vaccine waste management and the consequential public health threats.

Embracing context: Lessons from designing a dialogue-based intervention to address vaccine hesitancy.

Dialogue with people who are vaccine hesitant has been recommended as a method to increase vaccination uptake. The process of cultivating dialogue is shaped by the context in which it occurs, yet the development of interventions addressing vaccine hesitancy with dialogue often overlooks the role of context and favors relatively fixed solutions. This reflexive paper shares three key lessons related to context for dialogue-based interventions. These lessons emerged during a participatory research project to develop a pilot intervention to create open dialogue among healthcare workers in Belgium about COVID-19 vaccination concerns. Through a mixed methods study consisting of in-depth interviews, focus group discussions, and surveys, we engaged healthcare workers in the design, testing, and evaluation of a digital platform featuring text-based and video-based (face-to-face) interactions. The lessons are: (1) what dialogue means, entails, and requires can vary for a population and context, (2) inherent tension exists between helping participants voice (and overcome) their concerns and exposing them to others' ideas that may exacerbate those concerns, and (3) interactional exchanges (e.g., with peers or experts) that matter to participants may shape the dialogue in terms of its content and form. We suggest that having a discovery-orientation-meaning to work not only inductively and iteratively but also reflexively-is a necessary part of the development of dialogue-based interventions. Our case also sheds light on the influences between: dialogue topic/content, socio-political landscape, population, intervention aim, dialogue form, ethics, researcher position, and types of interactional exchanges.

Strategic silences, eroded trust: The impact of divergent COVID-19 vaccine sentiments on healthcare workers' relations with peers and patients.

BACKGROUND: Polarized debates about Covid-19 vaccination and vaccine mandates for healthcare workers (HCWs) challenge Belgian HCWs ability to discuss Covid-19 vaccine sentiments with peers and patients.Although studies have identified drivers of HCWs vaccine hesitancy, they do not include effects of workplace interactions and have not addressed consequences beyond vaccine coverage. METHODS: Interviews and focus group discussions with 74 HCWs practicing in Belgium addressed Covid-19 vaccine sentiments and experiences of discussing vaccination with peers and patients. RESULTS: Most participating HCWs reported difficulties discussing Covid-19 vaccination with peers and patients. Unvaccinated HCWs often feared that expressing their vaccine sentiments might upset patients or peers and that they would be suspended. Consequently, they used social cues to evaluate others' openness to vaccine-skeptical discourses and avoided discussing vaccines. Surprisingly, some vaccine-confident HCWs hid their vaccine sentiments to avoid peer and patient conflicts. Both vaccinated and unvaccinated HCWs observed that unvaccinated patients occasionally received suboptimal care. Suboptimal care was central in unvaccinated HCW unwillingness to express their vaccine sentiments to peers. Both vaccinated and unvaccinated HCWs described loss of trust and ruptured social relations with peers and patients holding divergent vaccine sentiments. DISCUSSION: Belgian HCW perceived Covid-19 vaccines as a risky discussion topic and engaged in "strategic silences" around vaccination to maintain functional work relationships and employment in health institutions. Loss of trust between HCW and peers or patients, along with suboptimal patient care based on vaccination status, threaten to weaken Belgium's, and by implication, other health systems, and to catalyze preventable disease outbreaks.

How Can Authorities Support Distributed Improvisation During Major Crises? A Study of Decision Bottlenecks Arising During Local COVID-19 Vaccine Roll-Out

Despite the increased importance attributed to distributed improvisation in major crises, few studies investigate how central authorities can promote a harmonic, coordinated national response while allowing for distributed autonomy and improvisation. One idea implicit in the literature is that central authorities could help track and tackle common decision bottlenecks as they emerge across "improvising" local authorities as a result of shared, dynamic external constraints. To explore this idea we map central functions needed to roll-out vaccines to local populations and identify and classify bottlenecks to decision-making by local authorities managing COVID-19 vaccine roll-out in Norway. We found five bottlenecks which emerged as vaccine roll-out progressed, three of which could feasibly have been addressed by changing the local authorities' external constraints as the crisis developed. While the national crisis response strategy clearly allowed for distributed improvisation, our overall findings suggest that there is potential for central authorities to address external constraints in order to ease common bottlenecks as they emerge across local authorities responding to the crisis. More research is to explore alternative centralized response strategies and assess how well they effectively balance centralized and distributed control. The study contributes to the growing literature examining the interaction between local and centralized response in crisis management.

Exploring the mechanisms behind HIV drug resistance in sub-Saharan Africa: conceptual mapping of a complex adaptive system based on multi-disciplinary expert insights

Background HIV drug resistance (HIVDR) continues to threaten the effectiveness of worldwide antiretroviral therapy (ART). Emergence and transmission of HIVDR are driven by several interconnected factors. Though much has been done to uncover factors influencing HIVDR, overall interconnectedness between these factors remains unclear and African policy makers encounter difficulties setting priorities combating HIVDR. By viewing HIVDR as a complex adaptive system, through the eyes of multi-disciplinary HIVDR experts, we aimed to make a first attempt to linking different influencing factors and gaining a deeper understanding of the complexity of the system. Methods We designed a detailed systems map of factors influencing HIVDR based on semi-structured interviews with 15 international HIVDR experts from or with experience in sub-Saharan Africa, from different disciplinary backgrounds and affiliated with different types of institutions. The resulting detailed system map was conceptualized into three main HIVDR feedback loops and further strengthened with literature evidence. Results Factors influencing HIVDR in sub-Saharan Africa and their interactions were sorted in five categories: biology, individual, social context, healthcare system and ‘overarching’. We identified three causal loops cross-cutting these layers, which relate to three interconnected subsystems of mechanisms influencing HIVDR. The ‘adherence motivation’ subsystem concerns the interplay of factors influencing people living with HIV to alternate between adherence and non-adherence. The ‘healthcare burden’ subsystem is a reinforcing loop leading to an increase in HIVDR at local population level. The ‘ART overreliance’ subsystem is a balancing feedback loop leading to complacency among program managers when there is overreliance on ART with a perceived low risk to drug resistance. The three subsystems are interconnected at different levels. Conclusions Interconnectedness of the three subsystems underlines the need to act on the entire system of factors surrounding HIVDR in sub-Saharan Africa in order to target interventions and to prevent unwanted effects on other parts of the system. The three theories that emerged while studying HIVDR as a complex adaptive system form a starting point for further qualitative and quantitative investigation. Supplementary Information The online version contains supplementary material available at 10.1186/s12889-022-12738-4.

Insights into vaccine hesitancy from systems thinking, Rwanda.

OBJECTIVE: To investigate vaccine hesitancy leading to underimmunization and a measles outbreak in Rwanda and to develop a conceptual, community-level model of behavioural factors. METHODS: Local immunization systems in two Rwandan communities (one recently experienced a measles outbreak) were explored using systems thinking, human-centred design and behavioural frameworks. Data were collected between 2018 and 2020 from: discussions with 11 vaccination service providers (i.e. hospital and health centre staff); interviews with 161 children's caregivers at health centres; and nine validation interviews with health centre staff. Factors influencing vaccine hesitancy were categorized using the 3Cs framework: confidence, complacency and convenience. A conceptual model of vaccine hesitancy mechanisms with feedback loops was developed. FINDINGS: A comparison of service providers' and caregivers' perspectives in both rural and peri-urban settings showed that similar factors strengthened vaccine uptake: (i) high trust in vaccines and service providers based on personal relationships with health centre staff; (ii) the connecting role of community health workers; and (iii) a strong sense of community. Factors identified as increasing vaccine hesitancy (e.g. service accessibility and inadequate follow-up) differed between service providers and caregivers and between settings. The conceptual model could be used to explain drivers of the recent measles outbreak and to guide interventions designed to increase vaccine uptake. CONCLUSION: The application of behavioural frameworks and systems thinking revealed vaccine hesitancy mechanisms in Rwandan communities that demonstrate the interrelationship between immunization services and caregivers' vaccination behaviour. Confidence-building social structures and context-dependent challenges that affect vaccine uptake were also identified.