By the way, herd immunity doesn't mean that we are suddenly free of risk. It just means the virus can't travel through our community so easily. Someone in the 40% non-immune group can still be infected by any traveller who brings it in from overseas and touches a handrail. I suppose no visa without antibody certificate could limit the risk but for the non-immune overseas travel would be inadvised or disallowed. Only a vaccine will really solve the dilemma or effective treatments..
