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Facilitating Controlled Temperature Chain Strategies for Last Mile Vaccine Transport

Team Members:
  • Aaron Chang
  • Amanda Valledor
  • Allison Moyer
  • Dominic Thomas
  • Jin Chung
  • Paola Donis
  • Rajiv Deshpande
  • Erik Tan
  • Aitana Juan, MSc


To streamline the workflow and increase adoption of controlled temperature chain (CTC) processes by NGO’s and country MOH’s, we have designed and developed a cost effective vaccine time indicator (VTI) which indicates vaccine stress due to days spent outside the cold chain. The CTC considers each vaccine’s particular heat-stability and allows for transport and storage of vaccines outside the cold chain for a defined period of time and temperatures immediately before administration. While CTC can alleviate the impact of cold chain infrastructure problems and save 50 percent of the logistics costs of the current last mile vaccine system in developing countries, there are still issues with the current CTC delivery method. Our solution replaces the manual tallying system used to keep track of days in the current CTC protocol with an automated time indicator based on color-changing ink. The color change is accurate to within +/- 6 hours by the end of 4 days, making it optimized for the first CTC approved vaccine for meningitis A, MenAfrivac®. The per vial form factor and color scheme of our indicator integrates consistently with the current vaccine vial monitor that is found on all UNICEF vaccines to enhance usability and facilitate adoption. Lastly, our device extends the potential reach of CTC beyond single antigen mass campaigns to the traditional, multi-antigen day to day operation of community health workers. With the estimated 5-6 additional vaccines which will receive CTC approval with varying time requirements in the next 2 years, our device will facilitate the scalability and growing acceptance of CTC as the new standard of care in last mile vaccine delivery.

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