During the COVID-19 pandemic, when vaccines were first made available to individuals, healthcare organizations across the country rapidly stood up mass vaccine distribution sites. Our organization opened our largest site in the parking lot and livestock buildings of the county fairgrounds. Although we were indoors, the livestock buildings had large open doors for cars to drive through and only swamp coolers to keep the buildings cool. Once the vaccine doses were drawn up, they needed to be kept between 36° F – 77° F. With summer temperatures that exceed 120° F, we knew we needed a solution to keep individual doses at an appropriate temperature while also easily accessible to the staff that were responsible for vaccinating more than 2000 people per day.

I spent time at the fairgrounds observing the current process and limitations of things like table space, shelf space to store doses before they were picked up, and how staff moved through the space as a whole. Through expert interviews with the lead pharmacist and operational staff as well as secondary research on the requirements for storage, I ensured I was clear on the target temperatures and safe handling. My goal was to design something that could keep the vaccines at temperature for at least four hours, be used from pharmacy to delivery, and that was easily handled by staff and volunteers (e.g. avoid latches or large cumbersome boxes). Through analogous inspiration, I learned that the best way to keep things at fixed temperatures was to fill the container as much as possible​, limit opening and closing the container​, cover all sides of the container with ice or another cold source, and pre-chill the container before adding the item that needs to be kept cold. Unfortunately, some of these suggestions were more difficult to implement given the needs of the clinical staff at the distribution site, so I tested multiple configurations to find the best potential solution.

Using an oven to simulate sustained temperatures of 115° F - 125° F, I tested several configurations of coolers (multiple sizes and both hard-sided and soft insulated envelopes) and ice packs (various brands and sizes, as well as foam and gel bases). Ultimately, I identified that the smallest commercially available hard-sided cooler (a 5-quart cooler with a handle) with two gel ice packs (one taped to the inside of the lid and one at the base with a cardboard buffer for the vaccine to rest on top of) with two foam ice packs propped on the sides accomplished our goal. It maintained the appropriate temperature range for more than 5 hours, did not require pre-cooling the ice chests, would allow the lid to be partially propped open for the entire time, and cost less than $15 per set. We tested the configuration with providers at the fairground, and they had no concerns about the utility and were grateful for the accommodations for ease of use like not having to close the lids.