We all know that most vaccines must be kept refrigerated at frozen or near-freezing temperatures to remain stable. That’s a problem when you consider that there isn’t enough refrigerated space in the world to store 7.8 billion vaccine doses. In addition, it’s highly anticipated that many of the vaccines that are being tested right now—or that are in early development stages—are going to need multiple doses, which further complicates the logistics of rapidly delivering vaccines to billions of people.