Controlled temperature chain for vaccination in low- and middle-income countries: a realist evidence synthesis

The WHO Controlled temperature chain: strategic roadmap for priority vaccines 2017–2020 provides a descriptive frame- work explaining how controlled temperature chain can lead to greater, and more equitable, immunization coverage for eligible vaccines.2 Here we use a realist review method to synthesize evi- dence from controlled temperature chain experiences to identify key priorities for future research. We also establish what may be needed to promote stakeholders’ interest for greater controlled temperature chain uptake in low- and middle-income countries.