Challenges in vaccine rollout linked to cooling

Approximately 2.7 billion people would lack dependable access to vaccines as a result of insufficient supply chains and logistics capabilities related to cold chains.

Even though supply challenges are the primary vaccine delivery constraint, the scale of the cold chain challenge to reach herd immunity, even at conventional storage temperatures between 2°C to 8°C, is still immense and has exacerbated existing cooling access gaps and created new ones. The herd immunity threshold for COVID-19 has been estimated to be at least 60–70 percent, which translates into 4.7 to 5.5 billion people. 

Challenges could also persist if, given the emergence of mutations and unknowns on the longevity of immunity, regular booster shots are required over time. India has one of the world’s largest routine immunization programmes targeting 29 million pregnant women and 26.7 million newborns every year, yet this is far from the scale needed to immunize India for COVID-19. [13]

The inequalities between richer and poorer nations in vaccine distribution are clear, including secured vaccines and cold chains needed to distribute the vaccines. Ellen Johnson Sirleaf, the former President of Liberia and current Co-Chair of the Independent Panel for Pandemic Preparedness & Response (IPPR) recently expressed her disappointment that based on current plans, vaccines would not be widely available in Africa until 2022 or 2023. Similarly, the Economist Intelligence Unit forecasts that 85 poor countries will not have widespread access to COVID-19 vaccines before 2023, including all African countries with the exceptions of Egypt, Ethiopia, Gabon, Kenya, Morocco and South Africa. [14]

Temperature control and vaccine cold chains are certainly a key contributing factor. A recent DHL logistics study concluded that even with conventional cold storage requirements, the proportion of the world’s population with good access to a vaccine, based on available logistics and supply capabilities, would only be about 70 percent. On this basis, approximately 2.7 billion people would lack dependable access to vaccines as a result of insufficient supply chains and logistics capabilities related to cold chains. [15]

Health facility electricity access

The World Bank surveyed 730 health facilities in six countries (Cambodia, Ethiopia, Kenya, Myanmar, Nepal and Niger) under its Multi-Tier Framework (MTF) approach in 2013. Off-grid solutions can be sufficient provided there is enough capacity, and moreover the surveys also highlight that approximately 25 percent of health facilities lack a primary source of electricity, in line with estimates from previous studies (Figure 3.2). Additionally, the surveys showcase significant differences between countries, with half or more of health facilities in Cambodia, Myanmar and Niger relying on an off-grid power solution. The surveys also highlight that grid power does not always equate to quality and reliable electricity, with 25 percent of surveyed on-grid health facilities reporting outages that affect health facilities’ ability to offer health services. Unreliable power and voltage surges contribute significantly to equipment breakdown and can cause vaccine losses with associated human health implications.

Figure 3.2: Electrification of health institutions in select MTF countries, by source (2013)

Electrification of health institutions


Sub-Saharan Africa

In Sub-Saharan Africa, where vaccine cold chain challenges are significant, reliable energy access in hospitals and clinics is a key need. Long before the COVID-19 pandemic made daily headlines, a lack of reliable power in healthcare facilities was undermining the quality of healthcare for millions of people in Sub-Saharan Africa. While data on the size of the energy access gap in the health sector are sparse, a handful of multi-country studies all point in the same direction. A 2013 WHO-led review in 11 countries in Sub-Saharan Africa estimates that one in four health facilities had no access to electricity at all, [16] while only 28 percent of health facilities and 34 percent of hospitals were considered to have ‘reliable’ electricity. A different study [17], focusing on ‘reliability’ of electricity in health facilities in low- to middle-income countries, estimates that 59 percent lack reliable electricity that would be necessary to power vaccine storage appliances that must be connected to electricity. Globally, the International Renewable Energy Agency (IRENA) has estimated that approximately 1 billion people rely on health facilities that have no electricity supply. [18]

To address challenges related to electricity access and power fluctuations that can impact the efficacy of vaccine refrigerators, Gavi has been engaged in the procurement of 65,000 off-grid-ready, solar direct-drive refrigerators  for nearly 50 countries and is now prioritizing them for last-mile vaccine delivery. To support the vaccine rollout under COVAX, in late 2020, UNICEF began purchasing 92,000 vaccine fridges, 11,325 of them solar-powered, as well as cold boxes and vaccine carriers. [19]

Such solutions are relatively expensive but are good in areas with limited energy access and help replace reliance on diesel. Portable cold boxes and refrigerated vans are other solutions that can support countries in reaching the last mile. Innovative business models can also make these solutions more accessible, in particular pay-as-you go (PAYG) models for technologies previously deployed in the agricultural cold chain.

The World Bank Group has made a USD 12 billion financing envelope available to developing countries to support the purchase of vaccines and strengthened health systems, including cold chains. One of the first approved projects provided support to Cabo Verde to purchase and deploy vaccines for 35 percent of its population, which included the financing of cold chain equipment and transport. [20] Similarly, the World Bank’s Energy Sector Management Assistance Program (ESMAP) also provides technical and investment support for reliable and climate-friendly health facilities and vaccine cold chains in Sub-Saharan Africa.


In India, improving energy access issues in primary health centres (PHCs) was identified as a key need for the COVID-19 vaccine rollout. It is estimated that approximately 28.2 million people living rurally depend on PHCs that do not have power supply. [21] A 2017 survey of Chhattisgarh province also revealed that 48 percent of PHCs, both on- and off-grid, experienced power deficits, with 90 percent reporting frequent power outages between 9am and 4pm. [22]

In the Indian province of Assam, 6.7 percent of PHCs lack a functional electricity supply and 10.6 percent lack a connection to an all-weather road. Moreover, 62.3 percent of sub-health centres at the district level lack a functioning electricity supply. [23] In addition to reliability and connectivity, a lack of training and technical knowledge can be an impediment to the proper use of cooling equipment. According to official data, around 6.5 percent of COVID-19 vaccines have gone to waste to date, with four states and a Union Territory having much higher levels of wastage: Telangana (17.6 percent), Andhra Pradesh (11.6 percent), Uttar Pradesh (9.4 percent), Karnataka (6.9 percent) and Jammu & Kashmir (6.6 percent). [24] The high wastage rates are mainly attributed to a lack of trained personnel and planning at site level with not enough people coming to get vaccinated, causing opened vials go to waste. [25] In the Cachar district of Assam, approximately 1,000 doses of the Covishield (AstraZeneca) vaccine were spoiled at the Silchar Medical College and Hospital because they were improperly stored at temperatures that were too cold. These vaccines were unintentionally frozen, rendering them unusable, likely due to a lack of staff training. [26] To mitigate these issues in the province, the efficiency and efficacy of solar vaccine fridges for COVID-19 vaccines were tested during a January 2021 polio vaccination drive targeting 4.7 million children. The units being tested can maintain a 2°C to 8°C temperature range for seven days after charging for one day in the sun. [27]

Even in richer countries and in those that do not consistently experience high outside temperatures, access to reliable refrigeration that can store vaccines at sub-zero temperatures is not a given. Mendocino County California’s Ukiah Valley Medical Center was forced to distribute more than 800 Moderna vaccines in two hours after a freezer was found to have malfunctioned, bringing the doses up to room temperature. [28]

Notes and references

13  Roadmap for achieving 90 percent full immunization coverage in India, Ministry of Health & Family Welfare, Government of India, January 2019. Link 
14  “More than 85 poor countries will not have widespread access to coronavirus vaccinations before 2023,” The Economist Intelligence Unit, 27 January 2021. Link
15  DHL White Paper, ‘Delivering Pandemic Resilience: How to secure stable supply chains for vaccines and medical goods during the COVID-19 crisis and future health emergencies.’ DHL, September 2020.
16  Adair-Rohani, Heather et al, ”Limited electricity access in health facilities of Sub-Saharan Africa : a systematic review of data on electricity access, sources, and reliability, » Global Health : Science and Practice, August 2013. Link
17  Cronk, Ryan and Jamie Bartram, ”Environmental conditions in health care facilities in low-and middle-income countries: Coverage and inequalities,” International Journal of Hygiene and Environmental Health, Volume 221, Issue 3, April 2018. Link 
18  “Healthcare,” International Renewable Energy Agency. Link
19  UNICEF Gearing Up for Historic Immunization Drive, UNICEF, 12 November 2020. Link
20  “First World Bank Support for COVID-19 Vaccine Rollout in Africa,” Press Release, World Bank Group, 11 February 2021. Link
21  Rawat, Mukesh, “How preparation for Covid vaccination drive is also an opportunity to make PHCs energy efficient,” India Today, 1 December 2020. Link
22  “Research Summary: Powering Primary Healthcare through Solar in India: Lessons from Chhattisgarh,” CEEW and Power for All, August 2017. Link
23  Rural Health Statistics 2018-19, Ministry of Health and Family Welfare, India. Via India Today. Link
24  Dey, Sushmi, ‘Centre urges states to minimise vaccine wastage,’ The Times of India, 18 March 2021. Link 
25  Sheriff, Kaumain, ‘Centre tracks COVID-19 vaccine wastage: Lack of trained personnel, planning at site level,’ Times of India, 19 March 2021. Link
26  Goswami, B and Kangkan Kalita, “Assam: Storied at sub-zero temp, 1,000 Covishield doses get spoiled at Silchar hospital,” The Times of India, 19 January 2021. Link
27  Kalita Kangkan, “Assam: Solar storages for Covid-19 vaccines to be tested during polio drive on January 31,” The Times of India, 20 January 2021. Link
28  Chan, Stella and Christina Maxouris, “After a freezer filled with Covid-19 vaccines broke, a California hospital scrambled to administer more than 800 doses in about 2 hours,” CNN, 6 January 2021. Link