The next 50 years of immunization in Africa: harnessing lessons from the COVID-19 vaccine rollout to build climate-resilient vaccine systems

¹Ministry of Health, National Public Health Agency, Freetown, Sierra Leone, ²Research and Scientific Division, Sustainable Health Systems, Freetown, Sierra Leone, ³Department of Internal Medicine, University of Port Harcourt Teaching Hospital, Port Harcourt, Nigeria, ⁴Department of Social and Behavioral Science, School of Public Health, University of Ghana, Legon, Ghana, ⁵Scientific Research Unit, Federal Medical Centre, Keffi, Nigeria, ⁶College of Medicine, University of Nigeria, Enugu, Nigeria, ⁷Medix Frontiers, University of Nigeria Enugu Campus, Enugu Nigeria

^&Corresponding author
Alpha Umaru Bai-Sesay, Research and Scientific Division, Sustainable Health Systems, Freetown, Sierra Leone

Perspectives    

Entangled epidemics and fragile progress

Africa's immunization journey over the past five decades represents one of the continent's most profound public health achievements. Vaccination programs have dramatically reduced childhood mortality and nearly eliminated several vaccine-preventable diseases (VPDs) [1]. Yet, this progress has repeatedly been disrupted by overlapping epidemics that expose systemic fragility. During the 2013-2016 Ebola outbreak in West Africa, the collapse of routine health services led to sharp declines in childhood vaccination coverage [2]. Liberia, Guinea, and Sierra Leone all witnessed dramatic surges in measles incidence, highlighting the indirect toll of Ebola on preventable illnesses. More recently, the COVID-19 pandemic exacerbated these vulnerabilities on a continental scale: in 2020 alone, 25 million children missed their first measles dose, and Africa recorded a resurgence of both measles and vaccine-derived poliovirus cases [3]. These recurrent setbacks highlight a sobering reality, immunization systems in Africa remain highly susceptible to systemic shocks, whether epidemiological, economic, or social. The phenomenon of “entangled epidemics,” where an emergent outbreak indirectly drives a surge in VPDs, illustrates how immunization failures are rarely isolated events but rather symptoms of broader structural weaknesses. Without deliberate reforms that anticipate these cascading crises, Africa risks cycles of progress followed by devastating reversals (Table 1). As we reflect on the continent's immunization journey, it becomes evident that resilience, not merely coverage, must define the next era of vaccine delivery. Sustaining hard-won gains requires systems that can absorb shocks, adapt under pressure, and continue to provide equitable access even amid crises.

Lessons from COVID-19: new delivery frontiers

The COVID-19 vaccine rollout in Africa, despite global inequities and late access, provided critical lessons on what it takes to sustain immunization during complex emergencies. While vaccine scarcity dominated headlines, equally important were the delivery innovations that emerged at national and sub-national levels. Countries leveraged non-traditional sites, schools, religious centers, markets, and workplaces, to expand reach beyond static health facilities. Door-to-door delivery and mobile teams proved indispensable in rural and hard-to-reach areas, demonstrating that flexible models can bridge equity gaps in ways clinic-based services cannot [4]. Digital technologies also came to the forefront: platforms for appointment scheduling, real-time data reporting, and targeted demand generation improved efficiency and responsiveness. Community engagement, often led by local leaders, was pivotal in overcoming hesitancy and misinformation, reaffirming the role of social trust in vaccine uptake. Collectively, these approaches demonstrated that immunization programs need not be rigid or facility-bound; they can be adaptive, people-centered, and responsive to dynamic challenges [5]. Importantly, many of these strategies were developed under duress, yet their effectiveness suggests they should not remain temporary fixes for crises. Instead, they represent a new frontier for African immunization systems, one in which flexibility, inclusivity, and community-driven models are institutionalized. The challenge now is to transform these emergency innovations into permanent features of routine programs, ensuring that future health shocks, whether pandemics or otherwise, do not derail vaccination progress. COVID-19 thus provided not only cautionary lessons about global inequities but also a roadmap for building resilient, accessible, and community-anchored immunization platforms in Africa.

From pandemics to climate shocks: a converging threat

While epidemics have historically disrupted immunization in Africa, the continent now faces a more profound and chronic challenge: climate change. The health impacts of climate variability are no longer hypothetical; they are already evident in the form of extreme weather events, recurrent droughts, flooding, and population displacement [6]. Each of these crises undermines immunization systems in unique ways. Floods and storms destroy health infrastructure, sever supply routes, and trigger power outages that compromise vaccine cold chains. Drought-induced displacement disrupts access to health facilities, leaving entire communities unvaccinated. Climate change also alters the geographic distribution of infectious diseases: warmer temperatures and shifting ecosystems expand the range of vector-borne and zoonotic illnesses, increasing demand for vaccines in regions previously unaffected [7]. This convergence of epidemiological and environmental threats magnifies the fragility of centralized, rigid immunization models [7]. A system reliant on fixed clinics and uninterrupted cold chains is ill-suited to a future where disruption is constant. The parallels with pandemics are striking; both create sudden surges in demand, destabilize supply chains, and disproportionately affect vulnerable populations. The difference is that climate change is not episodic; it is a permanent, escalating stressor. This reality demands a paradigm shift: Africa must reframe climate change not as a background risk but as a central determinant of vaccine strategy [8]. Immunization policies, research agendas, and financing models must explicitly integrate climate resilience. Just as COVID-19 forced the rethinking of pandemic preparedness, the climate crisis compels us to redesign vaccine systems to anticipate chronic environmental shocks while safeguarding equity.

Building climate-resilient vaccine systems

Looking ahead, the sustainability of Africa's immunization gains will hinge on the continent's ability to transition from fragile, reactive systems to resilient, adaptive ones. This transformation must be guided by three mutually reinforcing pillars (Table 2, Figure 1). The framework integrates three interdependent pillars: (1) adaptive delivery models (mobile clinics, outreach campaigns, school- and workplace-based vaccination, digital tracking for displaced populations) to ensure continuity of services during crises; (2) decentralized and green supply chains (solar-powered cold storage, renewable energy hubs, regional storage/production) to stabilize vaccine availability despite climate shocks; and (3) equity-driven governance (regional manufacturing, fair procurement systems, and community participation) to institutionalize fairness and accountability. Collectively, these pillars aim to safeguard vaccine access during pandemics and climate disruptions while promoting long-term sustainability and equity.

First, adaptive delivery models: immunization must evolve beyond static, facility-based services to outreach strategies that follow populations wherever they are, be it in displaced camps, informal settlements, or remote rural areas [5]. Approaches piloted during COVID-19, mobile clinics, school-based campaigns, door-to-door vaccination should be scaled and embedded as permanent delivery modalities [9]. Second, decentralized and green supply chains: traditional cold chain systems are vulnerable to power instability and climate disruptions. Africa must invest in solar-powered cold boxes, renewable energy hubs, and decentralized storage nodes capable of sustaining vaccines under extreme conditions. This approach simultaneously builds resilience and aligns with the continent's commitments to green growth. Third, equity-driven governance: the inequities seen during COVID-19 highlight the dangers of reactive, donor-driven vaccine allocation [10]. Equity must be institutionalized through transparent procurement, regional manufacturing capacity, and strong community engagement. Frameworks like Immunization Agenda 2030 provide an essential foundation but must be adapted with a climate-resilient lens. Achieving this vision requires more than technical fixes, it demands political will, sustainable financing, and regional solidarity. Through embedding flexibility, decentralization, and equity into every layer of immunization systems, Africa can ensure that vaccines remain accessible even in times of disruption. This shift is not optional; it is the prerequisite for safeguarding the next 50 years of immunization progress in a continent defined by both promise and profound uncertainty.

A unified call to action

The intertwined challenges of epidemics and climate change make clear that business-as-usual approaches to immunization in Africa are no longer sufficient. The lessons of the COVID-19 rollout: flexible delivery models, digital innovations, and deep community engagement must now be institutionalized as the foundation of resilient vaccine systems. At the same time, climate change must be treated not as a distant backdrop but as a defining determinant of health system design, shaping how vaccines are developed, stored, delivered, and governed. The next 50 years of immunization in Africa therefore, require a deliberate shift towards systems that are adaptive to disruption, decentralized in infrastructure, and uncompromisingly equity driven. This transformation will not occur without political leadership and sustained investment. Ministries of Health must integrate climate risk into national immunization strategies and adopt contingency planning as a standard practice. Regional bodies such as the African Union and Africa CDC should accelerate efforts to build vaccine manufacturing and supply chain capacity on the continent, reducing dependency on external markets during crises. Global partners, in turn, must move beyond emergency-driven aid and commit to predictable, long-term financing for resilient immunization platforms. Critically, communities themselves, through trusted local leadership and participatory governance, must be positioned at the center of decision-making to ensure that vaccine delivery is both accessible and culturally grounded. If these steps are taken, Africa can not only safeguard its hard-won gains against vaccine-preventable diseases but also set a global benchmark for climate-resilient immunization systems. The stakes are clear: failure to act risks repeated reversals in coverage, widening inequities, and preventable loss of life.

Limitations: this perspective is based on a synthesis of existing literature and expert reflections rather than primary empirical data. While this allows us to integrate cross-cutting insights across pandemics, climate change, and immunization, it is limited by reliance on secondary sources and interpretive analysis. Future empirical studies will be critical to validate and expand upon the strategies proposed here.

Competing interests     

The authors delare no competing interests.

Authors' contributions     

Alpha Umaru Bai-Sesay conceptualized the manuscript, led the writing, and coordinated revisions. Alpha Umaru Bai-Sesay, Chizaram Anselm Onyeaghala, Mark Anum Nortey, Abdullahi Hassan and Ebuka Louis Anyamene made substantial intellectual contributions to the development of key arguments, reviewed and revised multiple manuscript drafts, and approved the final version for submission.

Acknowledgments     

We acknowledge the contributions of public health teams across Africa whose frontline work continues to strengthen immunization systems. We also thank global and regional partners for their ongoing commitment to equitable vaccine access and health security on the continent.

Tables and figure     

Table 1: lessons from past epidemics and their impact on immunization in Africa

Table 2: building climate-resilient vaccine systems: proposed pillars, strategies, and stakeholders

Figure 1: framework for climate-resilient vaccine system in Africa

References