Pfizer’s COVID-19 vaccine has to be stored at an unheard of cold temperature even for Antarctica — minus 70 degrees Celsius, or 94 degrees below zero, Fahrenheit. Moderna’s can be kept a bit warmer, at “just” minus 20 degrees Celsius, or 4 below zero, Fahrenheit. But, for either vaccine, and particularly Moderna’s, this poses a problem for providers who will be administering the shots.
To get an idea of why the vaccines have to be frozen, NPR compares them to chocolates that melt easily. The reason the vaccines are so fragile is because they’re made with a technique that has never been used before, with messenger RNA, or mRNA, which turns your own cells into factory production lines to create a coronavirus protein. That, in turn, triggers immune responses in your body that are supposed to keep you from coming down with a severe case of COVID-19.
The problem is that mRNA is easily broken down, so it needs the freezing temperatures (such as the candy coating put on M&Ms) to keep it stable. Pfizer said it’s designed special packaging keeps the vaccines frozen with the help of dry ice. Even so, providers will still have to abide by strict guidelines, one of which says the freezer compartment storing the vaccines cannot be opened more than twice a day, and when opened, must be closed within one minute.
Once it’s thawed the vaccine can be kept refrigerated for five days. The whole situation makes distribution a challenge, too: Since the smallest amount you can order is 975 doses, that means the vaccines most likely will have to go to places capable of administering large numbers of vaccines in a short time period.
SOURCE: NPR November 17, 2020