I see you are asking Telegraph readers for their views on vaccine passports.
Your article seemed to be contradictory. It said we cannot rely on the vaccines to give us 100% protection so we need CV 19 passports. You then say we should rely on vaccines in a different way by only allowing vaccinated people to do certain things and give them a passport. How does this add to the protection, as in either case with or without the certificate we rely on the vaccination?
There is the residual issue of the small minority of adults who will not have the vaccine. Many of these will need to be given exemptions for health reasons or pregnancy, defeating the object you see in the control. If the idea has anything to recommend it it is simply to remove a few people that have no officially accepted reason for not being vaccinated from attending various events who might get the disease. They will presumably be offered the alternative of a test which may or may not be accurate. Given we are talking about a very high vaccine take up rate it seems likely there will anyway be little risk of picking up CV 19 as we will have something approaching herd immunity. In the dreadful event of a mutation that defeats the vaccine the system you recommend of course ceases to work and everyone is back at risk.
As you recognise there are technical issues about the use of apps and the necessary paper or card alternatives, and problems with the reliability of data back up. Some non believers without vaccination will operate to cheat the systems. Do we want to become a society where we will need to carry papers to do simple tasks and enjoy entertainments and sports? It is against all my instincts, born into a history based on the journey to freedom and liberty for all.