Apart from testing, administering the Coronavirus vaccine is the first major instance in which governments will be making use of a complex biomedical product. So far, they relied on prophylactic methods that date back hundreds, if not thousands of years. And once vaccination begins in earnest, the requirement to present a clean bill of health will likewise date back at least to the introduction of health passports in sixteenth-century Europe. But the success of simple, preventative measures relies on sufficient public infrastructures, adequate communication and trust in those who maintain them.