Effects of climate change on vaccine storage and cold chain logistics: a qualitative study in Ogun State, Nigeria

Abstract

Introduction

Climate change remains a global challenge posing a significant risk to the vaccine cold chain system logistics. It threatens vaccine potency due to inadequate storage facilities and ineffective vaccine distribution mechanisms, which are mostly affected by unpredictable environmental conditions. In Nigeria, this situation is worsened by unreliable electric power supply, frequently interrupted alternative power sources, poorly trained cold chain personnel, and inefficient management procedures. These factors contribute to low immunisation coverage rates and high disease burdens. Hence, there is a need to assess the effect of climate change on cold chain system logistics.

Method

Participants were cold chain officers across vaccine cold stores in Ogun State, Southwestern Nigeria. Data were collected via a 35-item semistructured in-depth interview guide. The effect of climate change on vaccine storage and cold chain logistics efficiency in Ogun State, Nigeria, was assessed. Data were manually and thematically analysed using the constructivist variants of the grounded theory methodology. Ethical approval and participants’ informed consent were obtained.

Result

Participants perceived that increasing ambient temperature variability constrained cold chain performance, resulting in equipment deterioration or damage. The vaccine distribution mechanism is mostly interrupted by difficult transportation systems caused by unpredictable weather changes. Policies are required around prompt replacement of damaged resources, equipment, continuous training of skilled workers, monitoring and surveillance system improvement.

Conclusion

Climate change significantly affected the efficiency of the cold chain system. Relevant policy implementation was highlighted as an essential step towards alleviating its effects.

WHAT IS ALREADY KNOWN ON THE TOPIC

• Climate change poses significant risks to vaccine cold chain logistics by impacting storage facilities and distribution mechanisms, especially under unpredictable environmental conditions.

• In Nigeria, these challenges are worsened by unreliable electricity, interrupted alternative power sources, poorly trained personnel and inefficient management.

WHAT THIS STUDY ADDS

• This study provides evidence of the negative effects of climate change on the vaccine cold chain by highlighting specific challenges expressed by cold chain officers and logistics bottlenecks posed by climatic factors.

• Solar-powered refrigerators in most cold stores are inefficient due to interrupted solar energy supply and equipment damage caused by climate change.

• Difficult transportation systems and unpredictable weather conditions disrupt vaccine distribution.

HOW THIS STUDY MIGHT AFFECT RESEARCH, PRACTICE OR POLICY

• Further research is needed to evaluate and design specific solutions to climate change problems affecting the vaccine cold chain storage and efficiency.

• Policies are needed for prompt equipment replacement, continuous worker training and improved monitoring and surveillance systems.

Introduction

The success of the first vaccine, smallpox vaccine, marked a revolution in the global effort against infectious diseases.¹ Vaccines have since been a significant component in the prevention of a host of vaccine-preventable diseases (VPDs) previously known to be deadly. With the emergence of more infectious diseases with epidemic and pandemic patterns, vaccines have become even more indispensable in preventing diseases in the present century much more than in previous times.²

Vaccines require optimal temperature throughout production, transport and administration to maintain their potency. At every stage, there must be strict adherence to best vaccination protocol and practices, which include the procedure of safe handling of vaccines from production until administration to the recipient.^{3 4} The vaccine cold chain system requires three interdependent components to function: transport and storage equipment, trained personnel and efficient management procedures. All three components must be fully functional to ensure safe vaccine transport and storage.4,6 The vaccine distribution system involves shipment from the point of production through to the vaccine end users, and this process is as important as ensuring optimal storage conditions.⁷ Transportation of vaccines is done through a variety of transportation means at the state and local government levels; the most common means of transportation is by road, which largely depends on the conditions of the roads at the time of transportation.

Climate change is presently one of the greatest global health concerns, posing both direct and indirect effects on human health.⁸ Global warming particularly poses a significant challenge to the achievement of the optimal temperature needed for the maintenance of the cold chain system. Since the preindustrial era, global temperatures have increased by at least 1°C, mainly due to human activities; meanwhile, the Intergovernmental Panel on Climate Change (IPCC) predicts a rise in global temperatures by at least 1.5°C between 2030 and 2052.^{9 10} Climate change will continue to affect the cold chain system. Hence, intentional efforts are required to adapt to its short-term effects and long-term impacts.

The effects of climate change on vaccines exposed to unregulated temperature are largely responsible for the reduction in potency, vector reproduction, alteration in human immune response to vaccination and disruption of immunisation service delivery at many levels.^{8 11} The direct and indirect effects of climate change increase the cost of vaccination, wastage of vaccines and delays in the actualisation of vaccination goals, ultimately affecting the realisation of Sustainable Development Goals.^{12 13}

One of the most globally documented cold chain system challenges is maintaining optimal temperature in the cold chain and the smooth running of cold chain logistics.² In Africa, the situation is much dire with the epileptic electric power supply, shortage of alternative power sources and lack of adequate storage facilities.^{14 15}

In Africa, one in five children is not completely vaccinated due to the unavailability of vaccines or suboptimal delivery to hard-to-reach areas.^{16 17} 30 million children suffer in Africa every year from causes related to VPDs. About 500 000 of these children succumb to these illnesses, resulting in death, making Africa the largest contributor (58%) to VPDs globally.¹⁸ The poor road network in Africa and adverse weather conditions make the transportation of vaccines to remote areas difficult.^{11 17} The seasonal flooding that occurs during the rainy season worsens the inaccessibility of areas in dire need of vaccines.¹⁹

Climate change poses significant challenges to various sectors, and its impact on the storage and distribution of vaccines in Nigeria is of paramount concern. Nigeria, with its diverse climate patterns, faces potential risks to the potency and efficacy of vaccines due to inadequate storage facilities and unpredictable environmental conditions. A study conducted in Southwestern Nigeria found that children living in hard-to-reach areas were less likely to receive vaccines than their counterparts in accessible areas.²⁰

The effectiveness of vaccines in preventing infectious diseases hinges on maintaining optimal temperatures throughout the vaccine cold chain from production to administration. Despite established best practices for vaccine handling, storage and transport, maintaining the required temperature range of +2°C to +8°C remains a significant challenge in Nigeria.¹⁵ This issue is exacerbated by the effects of climate change, which pose additional threats to the integrity of the cold chain, particularly in regions with unreliable power supplies and insufficient storage facilities.^{14 15}

In Southwestern Nigeria, as in every other region in Nigeria, these challenges are more pronounced due to frequent power outages, lack of sustainable alternative energy sources and inadequate cold storage infrastructure.¹⁴ Climate change intensifies these issues by contributing to global warming, which disrupts the maintenance of optimal temperatures needed for vaccine storage and integrity maintenance. The rise in global temperatures and increased exposure to solar ultraviolet radiation pose a risk of reducing vaccine potency, alteration of human immune responses and compromising the expected quality of immunisation service delivery.^{8 11} Furthermore, the direct and indirect health effects of climate change, such as increased incidence of infectious diseases, respiratory ailments and food insecurity, further strain the public health infrastructures.⁸

Climate change poses significant challenges to public health infrastructure in Nigeria, and its effect on vaccine storage and cold chain logistics remains an essential area of concern. Without doubt, the effectiveness of immunisation programmes relies mostly on the integrity of the cold chain system, a system designed to maintain vaccines at optimal temperature from the point of manufacture to administration to the vaccine recipient; however, the climate change phenomenon threatens this cold chain system. Hence, there is an urgent need to address the combined challenges of cold chain logistics and climate change to ensure the safe and effective delivery of vaccines in Southwestern Nigeria. Therefore, this study aims to shed light on the critical issue of climate change and its effect on vaccine storage and distribution in Southwestern Nigeria with the aim of safeguarding public health and improving immunisation outcomes in the face of climate change. In addition, by understanding the challenges and perspectives of key stakeholders, this research will provide valuable insights and recommendations to improve the resilience and effectiveness of Nigeria’s vaccine storage and distribution systems.

Research methodology

Study design

This study was a qualitative study using in-depth interviews (IDIs) to assess the effect of climate change on vaccine storage and cold chain logistics efficiency in Southwest Nigeria.

Study population

The target populations were cold chain officers, whose professional responsibility entails the maintenance and management of the cold chain system involving vaccine storage and distribution. Participating cold chain officers (listed in table 1) were selected across randomly selected local government areas (LGAs) in Ogun State, Nigeria

Table 1. Demographic characteristics of cold chain officers who participated in the study.

Participant	Years of experience	Age	Sex
P1	30 years	50s	Male
P2	8 years	40s	Female
P3	12 years	40s	Male
P4	10 years	50s	Female
P5	18 months	40s	Female
P6	10 years	40s	Male
P7	15 years	40s	Male
P8	7 years	40s	Female
P9	1 year	40s	Female

Sampling technique

A multistage sampling technique was employed for this study. Three LGAs were randomly selected from each of the three senatorial districts in Ogun State, which makes a total of nine LGAs across Ogun State. Each local government has a cold chain officer; hence, the cold chain officer of each selected local government was recruited into the study, making a total of nine participants.

However, when a potential participant (cold chain officer of any of the selected LGAs) who is eligible to participate in the study does not give consent, another potential participant within the same senatorial district was randomly selected for replacement. This procedure was repeated until the desired number of participants was achieved.

All cold chain officers of the cold store of the selected LGAs that were around during the study and have had at least 12 months of work experience within the cold chain system of the immunisation programme were included while those that did not give consent to be part of the study were excluded.

Data collection and analysis

In-depth interviews were conducted using a 35-item semistructured interview guide and digitally recorded. The audio recordings of the IDI were transcribed verbatim into a Microsoft Word document for analysis, and a unique individual ID was used in place of the respondent’s name. The data collected were analysed using narrative analysis. To ensure transcription quality, all transcripts were independently checked by the principal investigator against the original audio recordings, and grammatical errors were corrected. After the removal of identifiers, the data were analysed manually and thematically using the constructivist variant of the grounded theory methodology. Our qualitative approach emphasises generating insights through inductive analysis of data collection from participants, rather than relying on pre-existing theoretical frameworks. In this research approach, the focus is on understanding a social phenomenon through the lived experiences of participants using an iterative process of data collection and analysis. Grounded theory methodology requires the adoption of several strategies, including constant comparisons, coding, rigour, diagramming, identifying core themes and categorisation.21,23 The framework analysis approach was employed to guide our analysis which involves five key stages: familiarisation, identifying a thematic framework, indexing, charting, mapping and interpretation.²⁴ The findings were presented as themes aligned with the study objectives.

Result

Participant flow

Participants for the study were randomly recruited from the various LGAs of Ogun State, Southwestern Nigeria, specifically targeting individuals currently serving as cold chain officers. Nine participants, including five males and four females, aged between 40 and 54 years, with extensive experience ranging from 8 to 30 years, who met the criteria, were randomly selected across 9 of the 20 LGAs and enrolled.

Data collection was conducted to assess the effect of climate change on vaccine storage and cold chain logistics efficiency. The collected data were then thematically analysed using constructivist variants of grounded theory methodology, leading to the identification of key themes synthesised into the final report.

Theme 1: resource allocation

Effective vaccine storage and distribution in the face of climate change depend significantly on the allocation of resources to healthcare facilities. In Ogun State, the challenges posed by climate variability impact the adequacy and sustainability of these resources. This theme explored the multifaceted challenges affecting vaccine storage and distribution in Southwest Nigeria, particularly in the context of climate change. The financial implications, transportation issues, manpower shortages and equipment deficiencies collectively create a complex landscape for stakeholders. Responses from various participants shed light on the critical barriers they face and offered insights into potential strategies to overcome these challenges.

Subtheme 1.1: financial constraints

Financial constraints present a major barrier to adapting vaccine storage and distribution systems to the effects of climate change in Southwest Nigeria. Participants consistently highlighted the substantial costs involved in repairing or replacing damaged equipment, procuring new vaccine storage devices and recruiting additional manpower. For instance, one respondent noted, “Repairing or replacing damaged equipment would have financial implications as well as improving logistics” (30 years of experience, male). This underscores the immediate financial burden faced by local health facilities striving to maintain operational efficiency.

Additionally, there is a perceived lack of adequate financial support from funding stakeholders and the government. Funds intended for local health initiatives are often insufficient or misallocated by the time they reach the local government levels. One respondent articulated this frustration: "Most of the time, I see that they bypass our needs. If they are giving ten naira, maybe eight naira will come down from the higher levels. And, from eight naira that is supposed to come to facilities, maybe five naira will be made available” (10 years of experience, male). This indicates a significant gap in financial accountability and resource allocation, which hampers the effectiveness of local health initiatives.

These responses suggest that addressing financial constraints requires a multifaceted approach. There is a need for improved financial support from higher government levels, better allocation and management of resources, and strategic investment in infrastructure and manpower. By tackling these financial barriers, local health facilities can better adapt to the effects of climate change, ensuring more resilient vaccine storage and distribution systems in Southwest Nigeria.

Subtheme 1.2: transportation issues

Transportation issues are a significant barrier to the effective distribution of vaccines in Southwest Nigeria, particularly in the context of climate change. Participants frequently cited poor road conditions, especially during the rainy season, as a major challenge. One respondent pointed out, "The road conditions, exacerbated by climate change impacts such as increased rainfall and flooding, significantly hinder our ability to transport vaccines safely and efficiently to healthcare facilities” (1 year of experience, female). This underscores the critical impact of weather-related disruptions on transportation logistics.

The high cost of transportation further complicates vaccine distribution. As noted by a participant, “Transporting vaccines from Abeokuta to my LGA here is costly” (15 years of experience, male). The financial burden of transportation is not only due to poor road conditions but also to the distances that need to be covered to ensure vaccines reach all areas, including remote and rural locations. Additionally, some participants highlighted the lack of adequate transportation infrastructure and resources, such as ambulances or reliable vehicles. One respondent mentioned, "Ensuring that each facility has access to a transportation van would significantly mitigate the challenges posed by climate change on vaccine distribution” (1 year of experience, female). This statement reflects the need for better-equipped and more resilient transportation systems to handle the increased demands and challenges posed by climate conditions.

Another critical aspect is the insufficient funding for transportation from higher government levels. One participant expressed frustration with the financial support system, saying, "It still comes down to the issue of policy. We have policy, but when we are implementing, we are implementing to suit ourselves” (10 years of experience, male). This highlights the disconnect between policy formulation and practical implementation, leading to inadequate support for transportation logistics. The analysis of these responses reveals that transportation issues are multifaceted, involving both infrastructural and financial challenges. Poor road conditions, high transportation costs and inadequate infrastructure significantly hinder effective vaccine distribution. In addition, the systemic issues of insufficient funding and poor policy implementation exacerbate these transportation challenges.

Moreover, in urban centres, traffic congestion and the quality of road infrastructure are critical issues affecting timely vaccine delivery. Respondents from urban settings highlight the need for improved road maintenance and traffic management to ensure efficient distribution. One respondent noted, “Traffic congestion in urban areas delays vaccine deliveries, especially during peak hours” (30 years of experience, male). Similarly, the transportation challenges in rural areas are mostly due to inadequate road networks and difficult terrain, exacerbated during the rainy season. Participants noted that poor road conditions hinder access to remote communities, impacting the timely and safe delivery of vaccines. A respondent remarked, “In rural areas, impassable roads during the rainy season delay vaccine distribution to health facilities” (8 years of experience, female).

Subtheme 1.3: manpower shortages

Manpower shortages present a critical challenge in adapting vaccine storage and distribution systems to the effects of climate change in Southwest Nigeria. Participants highlighted the need for more trained personnel to manage the increasing demands placed on the cold chain system. One respondent emphasised, “There would be financial implications regarding procuring more equipment and recruiting more manpower so as to withstand the impact of climate change on our cold chain system” (8 years of experience, female). The shortage of skilled workers not only strains the existing workforce but also undermines the overall efficiency of vaccine distribution.

Likewise, the lack of technical knowledge on climate change among cold chain officers further exacerbates the manpower issue. One participant noted, “We do not have any specific engagement with the community on the effect of climate change on vaccine storage and distribution” (8 years of experience, female), indicating a gap in both awareness and expertise. This lack of knowledge limits the ability of cold chain officers to effectively adapt to and mitigate the effects of climate change on vaccine storage.

Demographic factors such as age and experience also play a role in manpower challenges. Younger and less experienced cold chain officers may lack the technical skills and confidence needed to address the complexities introduced by climate change. As one participant observed, “Government policies often lack adequate provisions for sustaining cold chain systems in rural areas” (30 years of experience, male), suggesting that younger officers might struggle more in less supported environments. This highlights the need for targeted training and support for younger staff to enhance their capacity to manage climate-related effects effectively; conversely, older and more experienced officers, while having the requisite knowledge, may be fewer in number and unable to meet the increased demand alone. Gender differences among the stakeholders seem insignificant in these challenges, as all are united in their concerns over manpower shortages and the effects of climate change on vaccine storage and distribution systems. Geographically, the disparity between urban and rural areas is stark. Rural locations often suffer from a more pronounced shortage of skilled manpower. One respondent highlighted, “Poor transportation system, low manpower and poor fund availability to run vaccine distribution logistics are the main challenges we face in our LGA” (8 years of experience, female). This underscores the compounded difficulties faced by rural areas, where logistical and financial constraints are more acute.

Cumulatively, these responses revealed that addressing manpower shortages requires a multifaceted approach. Recruitment efforts need to be intensified, with a focus on attracting and retaining skilled personnel across all regions. Training programmes should be implemented to enhance technical knowledge on climate change and its effects on vaccine storage. These programmes must be accessible to both new and existing cold chain officers to bridge the knowledge gap. Moreover, policies should aim to create a more inclusive workforce by supporting stakeholders and ensuring equal opportunities for professional development. Enhancing support for rural areas through targeted funding and resource allocation is also essential. This approach can help balance the manpower disparities between urban and rural settings, ensuring a more resilient and effective vaccine distribution system.

Subtheme 1.4: equipment deficiencies

Equipment deficiencies present a significant challenge in adapting vaccine storage and distribution systems to the effects of climate change. Participants highlighted the critical lack of functional cold chain devices and the dire need for modern, better climate change-resilient equipment. One respondent illustrated the severe shortage and maintenance issues faced in her LGA: “In my LGA, we have 18 storage devices, 9 of which are broken down and yet to be repaired” (12 years of experience, male). This deficiency not only undermines vaccine storage but also affects the distribution chain, leading to compromised vaccine potency.

Furthermore, the reliance on outdated technology exacerbates these challenges. Many facilities still use traditional refrigerators and are in urgent need of solar-powered alternatives, which are better suited to cope with power instability. A participant explained, “Some facilities don’t have cold boxes and geostyle, which are essential equipment needed for effective vaccine storage and distribution at the facility or outreach levels” (18 months of experience, female). This highlights the gap between current needs and available resources, which is still inadequate in some facilities.

Participants also pointed out that existing equipment often fails under extreme weather conditions, a situation worsened by the lack of immediate repair services. Another respondent noted, “There is inconsistency in policy enforcement, leading to lapses in infrastructure maintenance and equipment procurement” (18 months of experience, female). This lack of enforcement results in prolonged downtime for critical equipment, jeopardising vaccine integrity.

Addressing these equipment deficiencies requires substantial investment in modern cold chain technology and the establishment of robust maintenance protocols. Stakeholders emphasised the importance of adopting innovative technologies, such as solar-powered refrigerators, to enhance the resilience of vaccine storage systems. The overarching sentiment is clear: without addressing these fundamental equipment issues, the effectiveness of vaccine storage and distribution in the face of climate change may remain severely compromised.

Theme 2: stakeholder collaboration

Insights from various cold chain officers within Southwest Nigeria’s vaccine storage and distribution sector highlight both positive efforts and significant gaps in collaboration. Less experienced cold chain officers, particularly those newer to the field, express enthusiasm for collaboration but may encounter challenges navigating bureaucratic structures effectively due to their limited experience. In contrast, older cold chain officers with more experience often highlight historical challenges and bureaucratic hurdles that hinder effective collaboration.

Regarding geographic settings, cold chain officers from rural areas frequently highlighted disparities in collaboration compared with urban counterparts. They cited limited access to resources and communication channels, which hinder effective engagement with regional and national stakeholders. Conversely, cold chain officers based in urban centres benefit from closer proximity to government offices, non-governmental organisations and international organisations, facilitating more robust collaboration opportunities. While stakeholder collaboration shows potential through regular meetings and advocacy efforts, critical barriers related to age, gender, experience and geographic setting of the cold chain officers persist. Addressing these disparities requires targeted strategies to enhance inclusivity, improve communication channels and streamline decision-making processes across all governance levels and geographic locations within Southwest Nigeria.

Subtheme 2.1: policy and governance

Stakeholders across various demographics and settings express a critical view of current policies, citing challenges in implementation and resource allocation. As one respondent pointed out, “Government policies often lack adequate provisions for sustaining cold chain systems in rural areas” (8 years of experience, female), highlighting disparities in policy effectiveness between urban and rural settings. Furthermore, there is a consensus among stakeholders that governance structures need strengthening to ensure equitable distribution of resources and effective implementation of climate resilience strategies. This sentiment is echoed by stakeholders advocating for more inclusive policymaking processes that consider local contexts and community needs.

These cold chain officers identified gaps in regulatory oversight and enforcement, impacting the maintenance and operational standards of vaccine storage facilities. One of the respondents noted, “There is inconsistency in policy enforcement, leading to lapses in infrastructure maintenance and equipment procurement” (18 months of experience, female). Such insights underscore the urgency for transparent and accountable governance frameworks that promote sustainable practices and mitigate climate-related risks effectively. Moreover, some cold chain officers emphasised the role of international partnerships in shaping policy discourse and resource allocation, advocating for collaborative efforts to address systemic challenges and enhance resilience in vaccine distribution systems.

However, some cold chain officers indicated unawareness of existing policies or their specific implications for vaccine storage and distribution. This lack of awareness underscores the need for improved communication and education on policy frameworks among stakeholders involved in vaccine distribution across Southwest Nigeria. Addressing these governance challenges is crucial for building robust, climate-resilient vaccine storage and distribution systems capable of meeting future demands.

Theme 3: community engagement

Community engagement is a critical component of effective vaccine storage and distribution systems, especially in regions vulnerable to climate change like Southwest Nigeria. The involvement of community members, local leaders and health workers can significantly enhance the resilience and efficiency of these systems. This theme explores the various dimensions of community engagement, including awareness and participation, and the role of local partnerships in addressing the challenges posed by climate change. It examines how community involvement can be leveraged to improve vaccine storage infrastructure, ensure timely and equitable vaccine distribution and foster a culture of proactive health management. The insights gathered from respondents highlight both the successes and the areas needing improvement in community engagement efforts, providing a nuanced understanding of how to mobilise community support for better cold chain system management.

Subtheme 3.1: community awareness and participation

Findings indicate that community awareness and participation regarding the effect of climate change on vaccine storage and distribution are generally low across Southwest Nigeria. Many respondents reported minimal engagement with communities on this specific issue. For instance, one respondent noted, “We do not have any specific engagement with the community on the effect of climate change on vaccine storage and distribution” (8 years of experience, female). Another respondent echoed that, “There has not been engagement about the effect of climate change on vaccine storage and distribution with our surrounding communities” (18 months of experience, female). These insights highlight a significant gap in targeted communication about climate change effects on vaccine logistics.

However, some efforts to raise awareness exist, although indirectly. “Health education sessions at various facility outlets under our LGA often focus on the benefits of immunisation rather than on the specific challenges posed by climate change” (30 years of experience, male). “Community leaders and Routine Immunisation (RI) officers do hold meetings to educate community members about vaccination, stressing the importance of timely immunisation to prevent adverse events following immunisation” (1 year experience, female). The data reveal significant gaps in community engagement strategies. While there is an acknowledgement of the importance of informing communities about climate impacts on vaccine storage, structured and consistent approaches are lacking. This indicates that while general immunisation information is shared, specific discussions about climate change impacts are often overlooked.

Moreover, the level of awareness and engagement varies among different demographic groups. In some areas, community leaders and health workers take proactive steps to engage with their communities, despite limited resources and bureaucratic hurdles. Conversely, stakeholders in rural areas frequently highlight disparities in resource access and communication channels, which hinder effective community engagement compared with urban counterparts. To improve community awareness and participation, there is a need for targeted strategies that address these critical gaps. Enhancing communication channels, providing specific education on climate impacts, and ensuring inclusive engagement practices are essential steps towards building community resilience.

Subtheme 3.2: local responses and adaptation

Local responses to the effect of climate change on vaccine storage and distribution are varied and often improvisational, reflecting both the resourcefulness and the challenges faced by communities in Southwest Nigeria. Some cold chain officers highlighted proactive measures taken at the local level to adapt to climate effects. For instance, one respondent mentioned, “In some communities, local leaders and health workers engage in meetings to discuss and address the challenges of vaccine storage. They sometimes even repair faulty solar direct drive (SDD) refrigerators themselves, although this is supposed to be done with government approval” (10 years of experience, female). This underscores the community’s willingness to take ownership of their health infrastructure despite bureaucratic constraints.

Other responses point to a lack of structured adaptation strategies specifically addressing climate change. One respondent noted, “We have never raised awareness about the effect of climate change on vaccine storage and distribution. However, for general immunisation services, we use community mobilization methods to deliver health education on the benefits of immunisation” (8 years of experience, female). This indicates that while there are efforts to promote immunisation broadly, targeted strategies to address climate-related challenges in vaccine storage are still missing. Holistically, the data reveal significant gaps in policy and governance that hinder effective local adaptation. One participant highlighted, “There is inconsistency in policy enforcement, leading to lapses in infrastructure maintenance and equipment procurement” (18 months of experience, female). This inconsistency creates a fragmented response at the local level, where communities are left to devise their own solutions, often without adequate support or guidance from higher authorities.

Furthermore, the awareness and engagement levels vary greatly among different geographic settings. Cold chain officers in rural areas face distinct challenges, including limited access to training and resource centres compared with their urban counterparts. This disparity underscores the need for tailored interventions to empower rural cold chain officers through capacity-building initiatives and improved infrastructure support. In contrast, urban-based stakeholders benefit from proximity to policymaking hubs and international organisations, enhancing their capacity for advocacy and resource mobilisation.

To enhance local responses and adaptation to climate change, there is a need for comprehensive policy frameworks that support community-led initiatives, improved communication channels and targeted training for cold chain officers and health workers of the respective facilities. This would involve not only recognising the efforts already being made at the local level but also providing the necessary resources and support to ensure these efforts are sustainable and effective. Addressing these critical gaps will enhance the resilience of vaccine storage and efficient distribution systems in Southwest Nigeria, which can be significantly strengthened against the impacts of climate change.

Theme 4: best practices and innovations

In response to the multifaceted challenges posed by climate change on vaccine storage and distribution, respondents have identified best practices and innovations that enhance resilience and efficiency. These insights, drawn from local experiences and lessons learnt from other regions, provide valuable guidance for future improvements.

Subtheme 4.1: technological innovations

Technological advancements, particularly in solar-powered refrigeration, have significantly affected vaccine storage and distribution efficiency. The adoption of solar-powered refrigerators has been a pivotal innovation, helping to maintain vaccine potency and ensuring reliable storage even in areas with unstable power supplies. One respondent noted, “We have moved from ordinary refrigerators to solar-powered refrigerators, so I believe technology would get better and we would have a better storage system for the vaccines’” (12 years of experience, male).

The implementation of such technologies has mitigated some of the adverse effects of climate change, such as increased temperatures and power outages. This innovation not only ensures the efficacy of vaccines but also reduces operational costs associated with traditional refrigeration methods, which are often energy-intensive.

Subtheme 4.2: lessons learnt and recommendations

Drawing from both local experiences and successful practices in other regions, respondents provided numerous recommendations for enhancing climate resilience in vaccine logistics. One key lesson is the importance of continuous training and capacity-building for healthcare providers to handle climate-related challenges effectively. As one respondent recommended, “My recommendations are that the devices that are not working well should be replaced or repaired promptly. Also, the policy makers should ensure policies that would see regular training of the healthcare workers so that they can handle vaccine storage and distribution better” (12 years of experience, male).

Stakeholders also emphasised the value of community engagement and the role of local leaders in supporting vaccine distribution efforts. “The community leader and the Routine Immunization (R.I) officers hold meetings where the community leader addresses the community, particularly during mobilization activities. This approach ensures that community members are informed about the potential effect of climate change on vaccines” (1 year experience, female). This collaborative approach enhances community awareness and participation, thereby improving the overall effectiveness of vaccine storage and distribution systems.

Moreover, respondents highlighted the need for proactive governmental policies that prioritise climate resilience and allocate sufficient resources for sustainable practices. “Policies should be made to specifically provide more sustainable resources. Stakeholders should assist with providing the basic required equipment to combat the effect of climate change” (8 years of experience, female).

Theme 5: future trends and predictions

In exploring the future trends and challenges related to climate change and vaccine storage and distribution in Southwest Nigeria, stakeholders have offered valuable insights and predictions. These insights shed light on potential developments and proactive measures that can enhance the resilience of vaccine logistics systems amidst climate-related risks.

Subtheme 5.1: predictions for future trends and challenges

Cold chain officers expressed cautious optimism tempered by ongoing challenges. Many foresee that without addressing current issues, climate change could significantly disrupt the vaccine storage and distribution systems. As one respondent noted, “If the many challenges we currently have are not addressed, climate change would cause more chaos to our vaccine storage and distribution system” (30 years of experience, male). However, with adequate resources and effective management, respondents believe these challenges can be mitigated. Another respondent highlighted, “If the resources required are provided and are working well, we should be able to handle the future challenges that may be posed by climate change on vaccine cold chain system” (8 years of experience, female).

Looking ahead, there is a positive outlook towards technological advancements. Cold chain officers anticipate continuous improvement in storage systems, particularly the widespread adoption of solar-powered refrigerators. “I foresee a progressively better storage system within the cold chain system. We have moved from ordinary refrigerators to solar-powered refrigerators, so I believe technology would get better and we would have a better storage system for the vaccines” (12 years of experience, male). This optimism underscores the role of technological innovation in enhancing climate resilience and maintaining vaccine potency.

Subtheme 5.2: proactive measures for future climate-related risks

To prepare for future climate-related risks, stakeholders emphasise the importance of proactive measures across various dimensions. Multiple participants underscore the critical need for infrastructure improvement, advocating for a stable power supply and alternative energy sources like solar systems to mitigate the effect of erratic electricity on vaccine storage. One participant noted, “Improving infrastructure is crucial. We need stable power supply and alternative energy sources like solar systems to mitigate the impact of erratic electricity on vaccine storage” (30 years of experience, male). This sentiment reflects a widespread concern among cold chain officers about the foundational challenges posed by inadequate infrastructure in maintaining vaccine potency amidst climate challenges.

Furthermore, continuous capacity-building through training and support for healthcare workers on climate change adaptation strategies and vaccine management emerges as another key recommendation. Respondents stress the necessity of enhancing technical proficiency and preparedness among healthcare personnel to effectively manage climate-induced disruptions in vaccine logistics. This holistic approach aims to bolster the resilience of healthcare systems in Southwest Nigeria, addressing both immediate challenges and long-term sustainability in vaccine distribution efforts.

In addition to infrastructure and capacity-building, policymakers are urged to allocate sustainable resources and formulate robust policies that support long-term resilience in vaccine logistics. This broader systemic approach acknowledges the interconnected nature of climate impacts and healthcare delivery, aiming to fortify adaptive capacities across governance and operational levels. These proactive measures collectively aim to mitigate risks associated with climate variability, ensuring continuity and effectiveness in vaccine distribution efforts amidst evolving environmental pressures.

Discussion

This study highlights the significant effect of climate change on vaccine storage and cold chain logistics in Ogun State, Nigeria, as expressed by our study participants. Our findings underscore that rising ambient temperatures and unpredictable weather patterns frequently compromise vaccine storage conditions and disrupt vaccine transportation logistics. These challenges were reportedly exacerbated by unreliable electric supply, inadequate alternative power supply systems, limited technical capacity among cold chain personnel and poor resource management.

Our respondents reported the issue of inadequate funding and misappropriation of funds. The Nigerian cold chain is a grassroots system that operates at the local government level. However, government funding is mainly from the federal to the state level before reaching the local government.²⁵ The vaccine cold chain system requires a huge capital outlay, which the government and external donors fund. The government provides about 56% of funding, with 44% reliance on external donors, especially the World Bank, Gavi and some developed countries.²⁶ The economic downturn in Nigeria has led to increased interest rates, reduced national income and increased debt profile, which affects health sector budgetary allocation and implementation.²⁷

There have been documented gaps in resource allocation at the grassroots level; our respondents also allude to these gaps and the effect of this shortfall in combating the effects of climate change on vaccines.²⁶ The challenges posed by political whims and caprices, power tussles among agencies and the backdrop of external donor funding make rational budgetary allocation difficult in Nigeria.²⁸ Cold chain officers in our study believe there is a need for targeted government policies, which was also recommended in a recent study.²⁶

A study conducted in Southwestern Nigeria found that cold boxes were the primary cold storage transport equipment used in rural areas.²⁹ A similar study carried out in Osun State, Nigeria, also corroborated this finding, with cold boxes accounting for 45.7% of cold chain devices and only 31.4% of cold storage facilities having functional refrigerators.³⁰ Inefficient storage equipment exposes the vaccines to extremes of heat, which can affect their potency. A respondent noted that some facilities need essential equipment such as cold boxes and geostyles. Some equipment also breaks down under adverse weather conditions, as noted by multiple respondents, leaving vaccines exposed to inclement weather conditions. Additionally, our respondents noted that the cold chain system equipment needs constant overhauling, a significant challenge. This is plausible as studies have documented the poor maintenance culture of public infrastructure in Nigeria stemming from users' attitude to the appropriate use of public infrastructure and poor maintenance routine.^{31 32} The breakdown of about 50% of the storage devices in a cold store without prompt repair noted by a respondent is a pointer to the depth of these challenges.

The effect of inadequate cold storage facilities is not limited to vaccines alone; a study conducted in the Federal Capital City, Nigeria, showed that 66.7% of medicine cold storage did not conform to international standards.³³ Adverse environmental conditions and inefficient cold chain systems also affect agricultural product viability in Nigeria.³⁴ Our study found that some vaccine cold stores still use traditional refrigerators that are dependent on grid electricity. The epileptic power supply in Nigeria makes sustainability impossible. The paradigm shift is towards solar-powered refrigerators, which provide a viable option to on-grid power supply.³⁵ The increased intensity of sunlight from climate change can be positively harnessed to power storage refrigerators. Participants emphasised the benefits of adopting innovative technology like solar refrigerators to combat climate change’s effects on vaccine storage and distribution. Many respondents also stated the reduction in operational costs due to the adoption of innovative technologies in vaccine storage. Solar photovoltaics, thermoelectric coolers and micro cold storage systems are currently being used in other countries to increase the efficiency and reduce the environmental impacts of traditional cold storage systems.³⁶ The paradigm shift is towards more advanced digital technology, such as the Internet of Things (IoT) and digital identity.^{37 38} However, these technologies are being tested and may need more validation before widespread adoption.

Southwestern Nigeria experiences variable climate conditions with high ambient temperatures during the dry season and prolonged rainfall in the wet season, which affects the efficiency of the cold chain system.³⁹ Thus, key parameters for efficiency should be installed and monitored, such as battery storage capacity, panel efficiency, refrigeration unit efficiency and temperature control.⁴⁰ Solar radiance in Southwest Nigeria varies between 4 and 6 kWh/m²/day; thus, high-efficiency solar panels (≥18%) are essential to maintaining energy generation, especially during the rainy season.⁴¹ The battery storage capacity should be high enough to sustain uninterrupted refrigeration in the event of a power outage.⁴² Battery management systems must be in place to regulate charge cycles and protect against over-discharging to prolong the battery lifespan, especially in a low-resource setting, where replacing damaged facilities was noted as a significant challenge, as expressed by our study participants.^{2 43} Remote sensing data and geospatial analysis can serve as tools to optimise the placement of cold chain infrastructure in Southwest Nigeria by using data sets from previous explorations to guide site selection. High-resolution satellite images can be used to map population density and settlement patterns to aid identification of underserved and high-demand areas for vaccine storage and delivery.^{44 45} Geospatial data can be combined with satellite technology to locate good road networks to avoid flood-prone areas and maximise accessibility and reduce travel time for last-mile vaccine distribution.⁴⁵

The effect of flooding and torrential rain on Nigeria’s existing poor road network is well documented in the literature, reducing access to grassroots health interventions.¹⁸ Our respondents had challenges reaching remote areas due to adverse weather conditions, which are effects of climate change. The increased cost posed by these challenges strains the meagre running cost available at the local government, which can hamper prompt vaccine delivery to remote areas often plagued by many VPDs. Our respondents hinted that the unavailability of ambulances at some distribution units forced them to employ public transport systems. The poor implementation and translation of policies exacerbate the transport difficulties.

The need for adequate and well-trained manpower to combat the effect of climate change on the vaccine system cannot be overemphasised as these are the actors who implement policies. Respondents with higher levels of experience noted that junior officers needed more technical know-how to combat climate change. The training and retraining of cold chain officers constitute a significant component of the cold chain. Training of cold chain officers can increase their knowledge of handling cold storage and increase the efficiency of the system.⁴⁶ Good knowledge of vaccine cold storage systems is crucial; even more important is the application of the knowledge.⁴⁷ Disparities in power also exist between rural and urban areas. This disparity may be due to a lack of poor living conditions and inadequate incentives for health workers to consider serving in rural communities.

Community awareness and collaboration play a crucial role in ensuring the protection of vaccine systems against the effects of climate change. Community participation is a driver for adopting safe practices that will lead to increased vaccine adoption. One cold chain officer reported that communities sometimes repair faulty solar direct drives without waiting for government approval. Engaging various stakeholders in the community is an effective strategy to educate the community members on adopting behaviours that mitigate the effects of climate change. Our study found that urban communities had access to resources and thus took the lead in resource mobilisation in combating climate change.

Amidst the chaos that climate change has caused in our world today, forecasts appear to be glimpse; IPCC predicts that global temperatures will continue to rise.¹⁰ Cold chain officers in our study could not agree less based on the trends they have seen in the cold chain system over the years. A senior cold chain officer noted that the vaccine storage and distribution system will continue to suffer without a prompt and coordinated response to climate change. However, if resources are adequately mobilised, the stakeholders would be better equipped to combat challenges posed by climate change. Most participants had a uniting opinion on the role of adequate funding, infrastructure, policies, and adequate training of cold chain officers in combating the effects of climate change on the vaccine cold chain system.

Strengths, limitations and future research

Our study offers valuable insights into the effects of climate change on vaccine storage and cold chain logistics in Southwest Nigeria. Notably, the qualitative approach used in this study remains its unique feature as it captured in-depth perspectives from cold chain officers with varying levels of experience. The multistage sampling method ensured geographic representation across the study region, enhancing the validity of findings. Furthermore, the research highlights innovative strategies like adopting solar-powered refrigerators, which can serve as a template for similar regions facing climatic challenges.

However, the study relied on a small sample size of nine participants, potentially limiting the generalisability of findings. While the qualitative methodology was detailed, it lacks the statistical robustness of quantitative approaches. Additionally, the reliance on self-reported data introduces risks of recall bias and subjectivity.

Future research should consider mixed method approaches to corroborate qualitative findings with quantitative data. Studies involving larger samples across multiple regions in Nigeria would provide broader insights into cold chain logistics challenges. Investigating the long-term impacts of climate resilience policies and the effectiveness of innovative technologies, such as IoT-enabled systems, could yield actionable strategies. Exploring community-level engagement in vaccine logistics under climatic stress would further enrich this field of research.

Conclusion

Our study underscores the significant effects of climate change on vaccine storage and cold chain logistics in Southwest Nigeria. Financial constraints, transportation inefficiencies, manpower shortages and outdated equipment were the identified key challenges. Despite these issues, solar-powered refrigeration and proactive local responses were highlighted as innovative solutions for resilience.

Our findings revealed the critical need for improved funding, infrastructure upgrades and capacity-building initiatives to address the multifaceted challenges posed by climate change. Effective policies must be formulated and implemented to enhance resource allocation, prioritise sustainable practices and ensure equity across urban and rural settings.

The adoption of improved technologies and community engagement are key elements needed for strengthening cold chain systems. With adequate resources and stakeholder collaboration, it is possible to limit the effects of climate change, safeguard vaccine efficacy and improve immunisation outcomes. Our research provides a foundation for actionable interventions to enhance vaccine logistics in similar contexts globally.

Data availability statement

Data are available upon reasonable request.