I'll start by saying I am CEV. I also have Covid.
I do go out occasionally to medical appointments or for a drive. I sometimes see friends from at least 5m away in the front garden (as I'm unable to walk distance).
I've no idea how I've got this. I can not tell you how super careful I am with space, hand sanitiser / washing hands / PPE and basically not going out.
But I got Covid.
I'm not sure we can stop or contain Covid. I really have gotten to the the point where I believe that CEV are financially supported to stay isolated and everyone else gets on with it.