Open Access Government outlines the importance of facilitating robust vaccine cold chains to safeguard public health
Vaccines are among the most effective tools in modern medicine, yet their power to prevent disease is not inherent – it is conditional. Their effectiveness depends on more than scientific formulation or regulatory approval. It depends on the temperature.
From the moment a vaccine is produced, its integrity must be maintained through a delicate system of temperature-controlled storage and transport known as the vaccine cold chain. This chain represents one of the most complex and vulnerable elements of global immunisation infrastructure. Its failure – whether due to power outages, mishandling, or logistical errors – can render vaccines useless, threatening lives and wasting resources.
Vaccine cold chain integrity
Most vaccines require storage between 2 °C and 8 °C, with some requiring ultra-cold conditions of –70°C.
Deviations from these temperature ranges can denature active ingredients, leaving the vaccine ineffective.
However, cold chain failures are not just a scientific issue, they are a public health and economic crisis. COVID-19 vaccine logistics highlighted that poor temperature control, inadequate storage capacity, and insufficient real-time monitoring resulted in substantial vaccine wastage globally during the pandemic. In England alone, a government report revealed that around 4.7 million COVID vaccine doses were wasted by the end of October 2021.
In a global system where equity is already strained, cold chain mismanagement disproportionately affects low-resource settings, where refrigeration infrastructure and electricity may be lacking. Vaccine delivery in these regions is not just a supply chain issue – it is a human rights concern.
Storage and transport: A logistics challenge with clinical consequences
Cold chain logistics encompass multiple stages, including manufacturing, shipping, storage, regional distribution, and point-of-care delivery. At every stage, the integrity of the product must be verified and maintained. However, this is often easier said than done.
In low- and middle-income countries (LMICs) and remote regions, the challenges associated with vaccine delivery can be quite significant due to inadequate infrastructure. Equally, the transportation requirements for a polio vaccine, for example, which needs to be kept at 2°C, differ drastically from those of a COVID vaccine that can require ultra-cold storage at -70°C.
Vaccine freezers, which are essential for storing ultra- cold vaccines, necessitate considerably more energy than standard refrigerators. This energy demand makes them challenging to operate on generators or in areas lacking a consistent power grid. In many countries where electricity supply is erratic, ensuring the proper storage and transport of vaccines becomes a daunting task, as there’s no assurance of access to reliable mains power.
Inadequate road infrastructure can further complicate the cold chain. For example, in rural regions, it’s not uncommon for donkeys to be used for vaccine delivery. However, this poses a specific challenge: once a vaccine is taken out of a freezer, it must be delivered within a limited time frame. Delays caused by unstable terrain or severe weather conditions can render vaccines unusable, particularly in remote communities.
The situation becomes even more complex in countries experiencing conflict. Establishing a cold chain in such scenarios often necessitates creating ‘corridors of peace’ to facilitate safe delivery, ensuring that vaccines reach those who need them most despite the numerous logistical hurdles.
Even in higher-income countries, lapses occur. Vaccines stored in kitchen refrigerators, placed next to freezer coils, or left unrefrigerated for hours during transport can destroy product efficacy.
WHO’s strategic response: Technology, policy, and training
Recognising the cold chain as a critical component in vaccine delivery, the World Health Organization (WHO) has led efforts to improve cold chain management. For instance, the Performance, Quality, and Safety (PQS) initiative now prequalifies cold chain equipment, ensuring that UN agencies and Member States can ensure suitability for use in immunisation programs.
The WHO collaborates with countries and partners to enhance global vaccination coverage. This effort includes initiatives that were adopted by the World Health Assembly in August 2020. One key initiative is the Immunization Agenda 2030, which outlines an ambitious global vision and strategy for vaccines and immunization for the decade 2021–2030. This agenda was developed with input from thousands of contributors from around the world and builds on lessons learned from the past decade and addresses both ongoing and new challenges posed by infectious diseases.
As governments look to strengthen pandemic preparedness and scale up immunisation campaigns – from childhood vaccines to future pandemic responses—the cold chain must be treated as core health infrastructure. Investing in cold chain logistics is not just a scientific necessity – it is a governance responsibility. Policymakers must allocate funding, update regulatory frameworks, and build capacity to ensure that every dose counts.
