//A good idea but ,as it has already been shown, you cannot trust people to do that.//
Then that's their choice, danny. I cannot countenance this idea that everybody must take precautions to protect everybody else. The only person that can prevent you contracting the virus is you. You have to accept that it is widespread, you don't know who has it and who hasn't and if you keep your distance from everybody else, don't go out boozing in crowded venues, avoid busy public transport, practice good sanitizing and anything else you believe to be appropriate that's the best you can do. To expect everybody else to take measures so that they don't contract it and possibly pass it on to you is too much to expect. It's why "targeted protection" is needed and if you feel the need you can take advantage of it.
//There will always be the naysayers who think that Covid 19 does not affect them.//
They are not naysayers. A sizeable proportion of them will see little or no symptoms. I am also not a naysayer though if I contract it the chances are I will see quite severe symptoms. But I have taken the decision that I am not going to spend what's left of my life hiding behind the sofa. I take what reasonable precautions I think fit but I still live my life normally as far as I can. I go out; I travel on public transport; I frequent shops, pubs and restaurants. I would do a lot more (like travel abroad) if I were allowed to but I have has two holidays cancelled this year which I would have willingly taken. It's a matter of balance for what suits you and I've decided what suits me. I don't expect everybody else to do the same as me but I don't want to be accused of being selfish because I'm not sufficiently locking myself away so that nobody else contracts the virus. It is not possible to prevent it spreading and the sooner that is accepted the sooner we can move forward with a strategy that does not depend on thinking that it is.