First of all viruses have always mutated, that’s what they do. The people at risk should be quarantined and helped. The rest of the people can resume their lives.
The moment the digital vaccine passport is required for travelling (starting with aviation) people are going to figure out how to hack the system, create fakes, a way around the system. Maybe the aviation will even suffer with getting less passengers (because you need to wear a facemask during the entire flight).
The biggest problem is the technical problem, it is with the QR code. For example: you are vaccinated and have a vaccine pass (qr code), the private company you want enter (bar/ festival/ hotel/ car leasing/ supermarket etc) wants to scan your QR code, they will be able to access your private medical information. If and when the qr code is not configured the right way, private companies and people can have access to your medical information. My fear is that this will be over looked.
The source and more details on the technical QR code problems and Green Pass flaws. Austria is actively using the Green Pass. This is also in the works in the background in the Netherlands, this document confirms that.