Korean Researchers Develop Device to Confirm Safety of World's First COVID-19 Vaccine

Chemical Research Team Develops Device That Changes Color When Exposed to Temperatures Above Recommended Levels

Korea Research Institute of Chemical Technology, Biochemical Research Center (from left) Seong-Yeon Hwang, Je-Young Park, Tan-Hao (PhD candidate), and Dong-Yeop Oh are holding a vaccine mock sample equipped with an "ultra-low temperature change detection device."

[Asia Economy Reporter Kim Bong-su] The Korea Research Institute of Chemical Technology announced on the 12th that it has developed a temperature change detection device that allows immediate visual confirmation of whether COVID-19 vaccines have been safely stored and distributed at low temperatures.

Currently, among the vaccines distributed to prevent the spread of COVID-19, the Pfizer vaccine must be stored at an ultra-low temperature of about minus 70 degrees Celsius, and the Moderna vaccine must be stored at a low temperature of minus 20 degrees Celsius. The problem was that there was no intuitive way to confirm whether the vaccines had been stored and distributed at subzero temperatures. Since there have been no commercialized cases worldwide of mRNA vaccines that must be stored at ultra-low temperatures, related research had not been conducted. Conventional vaccines use weakened or inactivated pathogens, but mRNA vaccines work on the principle of teaching cells how to produce proteins or protein fragments that induce an immune response. The currently commercialized mRNA vaccines have the characteristic of needing to be stored at low temperatures.

The research team led by Drs. Park Je-young, Oh Dong-yeop, and Hwang Seong-yeon at the Korea Research Institute of Chemical Technology developed a simple device that attaches a container holding a specific compound next to the vaccine vial to check the storage temperature status of the vaccine. They utilized a substance made by mixing ethylene glycol and water. This substance is also widely used as coolant to prevent overheating in car engines. It has a melting point of minus 69 degrees Celsius; it remains solid below minus 69 degrees but begins to melt above that temperature.

The research team added a pigment to this substance so that its state can be visually confirmed, and placed white pulp powder as an absorbent underneath to observe the spreading of the pigment. In other words, when the substance is exposed to temperatures above minus 69 degrees and changes from solid to liquid, the liquid soaks into the pulp powder beneath the compound, causing the pigment to spread like ink on wet paper.

When applied to the Pfizer vaccine, which must be stored at an ultra-low temperature of about minus 70 degrees, the color spreads within 5 minutes if exposed to temperatures above minus 60 degrees, and changes can be detected within 2 minutes if exposed to room temperature (around 20 degrees Celsius). The longer the exposure time to temperatures higher than the recommended temperature, the more the color spreads, making it easy to determine the degree of exposure.

By mixing another compound, d-sucrose, with water instead of ethylene glycol, the device can be applied to the Moderna vaccine, which must be stored at minus 20 degrees Celsius.

The research team set the compound ratios so that the color does not spread during brief unavoidable exposure to room temperature during distribution or use. The color only spreads if exposed to temperatures above the recommended level for more than 2 minutes. When ethylene glycol and water are mixed at a ratio of 40% to 60%, even if the temperature rises above minus 69 degrees, the solid does not immediately turn into liquid but remains in a mixed solid-liquid state for a certain period, preventing color spreading from short-term temperature changes. This device cannot be manipulated because once exposed to room temperature and then returned to ultra-low temperature, it does not revert to its original state.

The results of this research were pre-published online in the American Chemical Society journal ‘ACS Omega’ and were selected as the cover paper for the March issue.

This content was produced with the assistance of AI translation services.