It helps to understand that the German constitution has a specific article saying that the state may not conduct any medical tests without your knowledge or consent under article 2 of freedom of physical integrity. But like the Canadian constitution, there is an out for the state. “Unless there is a law”. This page is an interesting read as it shows that with basic rights, the constitution has created a condition where the German government can run roughshod over its own constitution by redefining a thing or two or deciding a given condition, in this case a virus, allows them to do so.
Canada has a “not withstanding” clause which allows governments to ignore what laws they want as well. Only the US one has absolutes. And I think we can all see why now.