What is irrelevant again, because those officers will read the QR code with a computer. The computer can summarize to them how valid the vaccine still is.
There is no reason at all why a paper printed QR code can't tell exactly what vaccine you have taken, when you took it, who exactly are you, and what authority is authenticating the data. From there, any extra data is only needed at the time of reading.
There is no reason at all why a paper printed QR code can't tell exactly what vaccine you have taken, when you took it, who exactly are you, and what authority is authenticating the data. From there, any extra data is only needed at the time of reading.