Cold Shippers Keep COVID-19 Vaccines Viable

By Christina P. Hooton

COVID-19 vaccines are being administered in the U.S. at a pace of 3.02 million doses per day on average as of April 20, 2021, according to the Centers for Disease Control and Prevention.¹  Rapidly distributing and administering tiny vials of life-saving medicine on such a large scale is a unique challenge.

In addition to establishing the complex supply chain required for this massive undertaking, manufacturers and distributors must store the Pfizer-BioNTech vaccine at extremely cold temperatures. Others, like the Moderna and Johnson & Johnson vaccines, must also be stored at cold temperatures. To make this possible, a cold chain, or system for maintaining distribution at low temperatures, is employed.

A New Type of Vaccine

Both the Pfizer-BioNTech and Moderna vaccines work by introducing messenger ribonucleic acid (mRNA) into the body. The mRNA shows our bodies how to create a harmless protein identical to one on the virus surface. This “spike” protein is then seen by our immune systems as “foreign,” and we develop antibodies to the COVID-19 virus. But because mRNA is somewhat delicate, it must be stored at cold temperatures.

The Moderna vaccine must be shipped at –50º to –15ºC (–58º to +5ºF) and can be stored at that temperature for six months. Once thawed, it can be kept in a refrigerator between 2° and 8°C (36° and 46°F) for 30 days. The Pfizer-BioNTech vaccine must be shipped and stored at –70°C (–94°F), a temperature much colder than a standard freezer.²

While mRNA vaccines have long been studied for defense against a variety of diseases, including influenza, Zika, and rabies, this is the first time this type of vaccine has been approved for use and widely distributed.

Portable Freezers

Because not every clinic or vaccination site is easily accessible or equipped to handle the storage requirements of its vaccine, Pfizer developed a new, reusable shipping container that can hold between 1,000 and 5,000 doses and keep the vaccine cold for up to 10 days.

Each “shipper” is roughly the size of a suitcase and includes a space for dry ice, room for the vaccine, and a GPS temperature-enabled tracker to provide real-time location and temperature monitoring. A control tower monitors and tracks all shipments to make sure each one arrives at the right location on time and at the right temperature. If any of these variables are negatively affected during transit, corrective action can be taken.

The boxes can be used as temporary storage for up to 30 days if new dry ice is added every five days. To store the vaccine for longer periods, ultra-cold-temperature freezers can be used. Once removed from the shipper, the vials of vaccine can be stored in a regular refrigerator for up to five days.

Innovative packaging is just one of the many solutions contributing to one of the largest vaccination campaigns in history. It will be exciting to see what other developments we gain from this moment in time.

1.  (2021, April 20). See How the Vaccine Rollout Is Going in Your County and State. The New York Times[HM1] . Retrieved from https://www.nytimes.com/interactive/2020/us/covid-19-vaccine-doses.html

2. Fischetti, M. (2020, November 19). The COVID Cold Chain: How a Vaccine Will Get to You. Scientific American[HM2] . Retrieved from https://www.scientificamerican.com/article/the-covid-cold-chain-how-a-vaccine-will-get-to-you/