How the use of vaccines outside the cold chain or in controlled temperature chain contributes to improving immunization coverage in low- and middle-income countries (LMICs): A scoping review of the literature

Abstract

Background Most vaccines are recommended for storage at temperatures of +2°C to +8°C to maintain potency. Immunization supply chain bottlenecks constraints reaching populations with life-saving vaccines. The World Health Organization permits the use of vaccines outside the cold chain as “controlled temperature chain (CTC)” upon meeting certain conditions and has set targets to license more vaccines CTC by 2020. Objectives This scoping review aims to explore and synthesize the evidence in the literature on how the use of vaccines outside the cold chain or in a controlled temperature chain increases immunization coverage in low and middle-income countries (LMICs), with a focus on the timelines of the Global Vaccine Action Plan (2011-2020). Methods A systematic search of three online databases (PubMed, Embase, and Web of Science) due to their broad coverage of global health sciences retrieved 173 original peer-reviewed articles, of which 13 were included in the review having met our inclusion criteria. Results The majority of the studies were conducted in Africa (n = 9), followed by Asia (n = 3), and the least in the Pacific (n = 1). The different study designs captured included four non-randomized trials, three randomized trials, two simulation models, two cross-sectional studies, and one cohort study. Reported benefits included increased coverage, logistical ease, cost savings while vaccines remain potent. Conclusion Currently, only two vaccines have been licensed to be stored CTC. More needs to be done to get additional vaccines licensed for CTC and disseminate operational guidance to operationalize its use in low- and middle-income countries.

Management of COVID-19 vaccines cold chain logistics: a scoping review

“…There is a risk that the operation ceases, should any of the processes fail to run its course, which then jeopardises the business entity. Exposed biological products such as vaccines and equally other biological goods to unfavourable temperatures can damage the products and eventually render them being of no use [ 23 ].…”

“…In addition, inappropriate coordination with local organisations, lack of vaccine monitoring bodies, difficulties in monitoring and controlling vaccine temperature, and financial support for vaccine purchase were identified as the main challenges in the region of Asia [ 27 ]. Another area which is also under-researched is the use of vaccines in controlled temperature chain (CTC) or outside the cold chain (OCC) environments [ 23 ]. One study experimented on commercially available products, such as refrigeration container units, and retrofitted the test units to meet the vaccine storage temperature requirement.…”

A hybrid approach based on ELECTRE III‐genetic algorithm and TOPSIS method for selection of optimal COVID‐19 vaccines

“…Optimising the use of vaccines depends heavily on maintaining optimal storage conditions. A vaccine is now expected to remain stable at standard refrigerator temperatures of 2–8°C (36°–46 °F) for an average period of 1 week while shipping and long‐term storage conditions are expected to remain at standard freezer temperatures of −20°C (−4 °F; Dadari & Zgibor, 2021; Dumpa et al, 2019; World Health Organization, 2018). However, some vaccines are sensitive to freezing, some to heat and others to light.…”

Trends in Uptake and Impact of Thermostable Vaccines in Africa

“…The term Out of Cold Chain (OCC) implies the act of removing a vaccine out of the cold chain because the given vaccine is thermostable, without necessarily requiring approval from the regulatory bodies and without necessarily receiving prequalification from WHO. 28 It is regarded to be "off label "since it denotes that it does no longer follow the established vaccine manufacturer handling guidelines and the Expanded Program on Immunization (EPI) policies.…”