To continue from previous blog posts, the CDC posts a variety of guidelines related to temperature monitoring, measurement and best practices that are interconnected with many of our offerings. While these suggestions and comments are useful for general purposes, consult with the official CDC.gov website for the official guidelines.
The CDC's minimum recommendations for Temperature Readings/Documentation state that temperatures should be logged twice daily, preferable in the morning. Unfortunately, while this gives a nice "bi-daily" snapshot of the storage temperatures, it fails to account for temperature changes and fluctuations (which may compromise vaccines) in the 12-hour periods wherein readings are not recorded. It's unlikely that any provider would find these minimum guidelines acceptable for a sensitive vaccine, and we agree that this guideline is hardly a 'minimum' at all. As some vaccines have precise and more strict temperature requirements (variability of 6 degrees, for example), incremental monitoring surfaces as the optimal solution. Here's a "short" list of the vaccines that must be stored with a 6 degree temperature range, not including combination vaccines. DPaT Hepatitius A & B HPV Influenza (LAIV & TIV) IPV (Polio) MMR (Measles, Mumps, Rubella)
As for intervals, "CDC recommends the use of a continuous monitoring device/digital data logger to record and store temperature information at frequent programmable intervals for 24-hour temperature monitoring."
This sheds light on the importance of incremental monitoring, and the need for "around-the-clock" monitoring. We all understand the importance of temperature (as it relates to vaccine storage), but can we really afford to check temperatures once every 12 hours? CDC might admit that their own minimum requirements are hardly sufficient for vaccine storage of any kind, and their additional suggestions prove that the minimum is hardly relevant for vaccine storage in general. In truth, a programmable interval should be set for each individual storage unit, as certain units may house vaccines that are more/less sensitive to temperature change (and thereby, require less supervision than others).
Along with incremental monitoring, the CDC also recommends the use of buffer vials, specifically stating that "The digital data logger should be connected to a detachable thermometer probe encased in a biosafe glycol-filled vial. The data logger's active digital display should be attached to the outside of the storage unit to allow reading temperatures without opening the door".
We've talked about the difference between glycol and sand buffer vials in a previous blog post, viewable here. With either choice, buffer vials are another important piece of the monitoring puzzle.
Finally, you may be wondering, "what exactly is incremental monitoring" or "what are the programmable intervals that I should be setting for my temperature readings?" The CDC recommends 15 minute monitoring, or four logs per hour, for proper supervision of storage temperatures. Their minimum requirements are set at a far distance from this suggestion, and the truth is that it depends on the vaccine being stored. Make sure to have a complete emergency plan in preparation for temperature monitoring failures, whether the cause is human, mechanical or a simple power outage. Many temperature monitoring devices (including our own Cellular edition) are specifically designed for fail-safe operation, and with correct use of incremental monitoring, you may detect a potential temperature problem before it develops into a disaster.