It is a major global health challenge to get life-saving vaccines to children in hard-to-reach parts of Africa and Asia. These vaccines must stay cool during transport, yet it is not always possible to prevent heat exposure. Historically, health workers had no means of determining whether such heat exposure had damaged the vaccines and caused them to lose potency. But Vaccine Vial Monitors, or VVMs, changed that. A VVM is a small temperature monitor, no bigger than a dime, that adheres to a vaccine vial to indicate whether the vaccine has been rendered ineffective by excessive heat exposure. The benefits of using VVMs are two-fold: children only receive viable vaccines, and health workers do not discard viable vaccines because they are uncertain about heat exposure damage. VVMs were first developed in 1990, and by 2017, over 6.6 billion VVMs had been used. However, VVMs had a long and uncertain journey that spanned almost 30 years between 1979, when the World Health Organization (WHO) put out a call for such a technology to be invented, and 2007, when there was mass adoption by vaccine manufacturers. This case focuses on the efforts made, and challenges faced, by the many public, social, and private sector partners who collaborated to take this relatively simple social innovation to global scale. These partners included international governmental health bodies such as WHO and UNICEF; the non-governmental organization PATH, which spearheaded and guided the efforts; and Temptime, the private company that invented the technology. Though sometimes at odds with each other, the partners had to convince the many different vaccine manufacturers to buy and use the VVM product. This required continually adapting technology design, reshaping business partnerships, and rethinking cost/pricing models. VVMs had saved over 160,000 children's lives by 2012 alone, but success had in no way been a sure thing.
