US pharmaceutical giant Pfizer said today that it is applying for permission from the US Food and Drug Administration (FDA) to store COVID-19 vaccine at the temperature of a normal medical refrigerator.
New tests show that when temperatures are between -25 and -15 degrees Celsius, Pfizer’s mRNA vaccine remains quality for 2 weeks. It will be a new door for developing countries to access this vaccine.
It’s as difficult as wrapping the Antarctic winter in a cardboard box
Shortly after the pharmaceutical giant Pfizer planned to bring its COVID-19 vaccine to market in November last year, the carriers knew they were on the verge of facing a difficult problem. Based on mRNA technology, the Pfizer vaccine needs to be stored at around -70 degrees Celsius.
Pfizer immediately summoned a team of experts to be able to design specialized boxes to deliver the COVID-19 vaccine. Basically, it’s like wrapping the Antarctic winter in cardboard boxes.
Dry ice or CO2 condenses itself to solid form at -78 degrees Celsius. If poured into a box of 2 kg dry ice and replaced every 5 days, the Pfizer vaccine can be stored for 15 days.
After the recipe was shared with shipping carriers, UPS immediately increased the capacity for dry ice production in the centers to 1,200 pounds per hour. FedEx has also put more than 5,000 distribution centers, 80,000 delivery vehicles and 670 aircraft ready for COVID-19 vaccine delivery missions.
But a Reuter survey found that only 15% of carriers confidently accepted Pfizer’s vaccine orders.
The Pfizer vaccine storage dry ice box design has been likened to the Antarctic winter pack in a cardboard box.
In India, a country of more than 1 billion people, a network of 28,000 cold storage facilities has been built for conventional vaccination campaigns. But experts say there is no one company here capable of transporting goods in conditions below -25 degrees Celsius.
Pfizer’s mRNA vaccine is therefore mainly being distributed to developed countries where modern logistics systems are located. It is completely out of the reach of other countries.
But now, opportunities seem open to developing countries as well. Pfizer said today that it is applying for FDA approval so it could have an additional short-term storage option for the COVID-19 vaccine. Accordingly, conventional medical freezers and refrigerators (with temperatures between -25 and -15 degrees C) can be used to preserve Pfizer’s mRNA vaccine for up to 2 weeks.
Why does the mRNA vaccine need to be stored in super cold temperatures?
Earlier, the FDA said Pfizer’s COVID vaccine, developed with German pharmaceutical manufacturer BioNTech, needed to be stored in an ultra-cold freezer, at temperatures between -60 and -80 degrees Celsius. mRNA particles contained in vaccines are very susceptible to spoilage.
It can be broken down by small amounts of enzymes present in the environment, and even a human breath or dead skin dust can contaminate the vaccine with enzymes and cause it to fail.
So, despite being produced in the cleanest factories in the world, where workers go inside needing to shower, wear protective gear, wrap hair in cloth bags and wear glasses and masks, dose of mRNA vaccine still does not avoid the risk of degradation enzyme infection.
At the time, in order to preserve the vaccine, the FDA and Pfizer’s scientists decided to keep it at the same temperature as the cell’s storage temperature. The goal is to slow down the breakdown of mRNA, because low temperatures mean that biochemical reactions are slower. And the lower the temperature, the more effective a vaccine can be compared to when it was first shipped.
Pfizer workers in a cold storage room for COVID-19 vaccine.
Finding the optimal temperature to store vaccines requires companies like Pfizer to run a lot of tests. They need to keep the doses of the vaccine in refrigerators at different temperatures, then check the integrity of the mRNA, even inject them into volunteers to confirm its ultimate potency.
During the COVID-19 pandemic, the mRNA vaccines we are currently using were also those based on the brand new mRNA technology, licensed for the first time. As a result, their preservation experience is largely absent and constantly needs to be updated.
Luckily, the temperatures that scientists have found to store the mRNA vaccine are rising.
Access has opened up for developing countries
In its latest statement, Pfizer said it had submitted new documents to the FDA that showed its COVID-19 vaccine can be kept in the normal freezer for up to 2 weeks. It is a temperature range from -25 to -15 degrees Celsius. This is also the threshold temperature that cold storage and delivery systems in developing countries can reach.
For comparison, Moderna’s vaccine also uses mRNA technology but only requires storage conditions at -20 degrees Celsius. At this temperature, Moderna’s vaccine can keep its quality for 6 months. Increase the temperature to 2-8 degrees Celsius, equivalent to a conventional refrigerator, it can still be used within 30 days.
AstraZeneca’s vaccine can even be kept in a regular refrigerator for up to 6 months. At this temperature, the Pfizer and BioNTech vaccines will fail within 5 days.
“We have been continuously performing vaccine stability studies to support their commercial distribution. The goal is to make vaccines as accessible as possible, making it available to every hospital, clinic, every citizen in the United States and around the world “, Pfizer CEO Albert Bourla said.
Now, if the FDA approves their request, their COVID-19 vaccine logistics and transportation will become a lot easier. “If approved, this new storage option will give pharmacies and immunization centers more flexibility to manage vaccine supplies.“, Bourla added.
Pfizer is currently continuing to experiment to see if their vaccines can extend shelf life at higher temperatures.