Improving Vaccine Safety by Using an Algorithmic Model as a Replacement for a Physical Thermal Buffer
Conventional practice in vaccine storage is to insert a temperature probe into a bottle of glycol, or another equivalent thermal buffer medium, to simulate the temperature experience of the stored vaccine, rather than just the air temperature. Such a thermal buffer is intended to reduce false alarms so that the drug manager will know with higher confidence that a temperature alert is an event requiring action. While necessary and appropriate to correctly monitor the storage conditions, it is a practice that is messy, inconvenient, and costly, and can result in reports that diverge from the actual experience of the stored inventory. This paper explores the use of a mathematical algorithm to reproduce the behavior of a physical thermal buffer medium. The paper describes the algorithm and reports the degree to which it accurately simulates the experience of a 20-ml glycol container. The algorithm is shown to be highly predictive of the temperatures measured inside a container containing glycol.