Fact check - please correct me if I am wrong19 Apr 2020 09:20
We don't yet know if:
1. all C-19 infections result in antibody production;
2. antibodies last more than a few days, as there are reports that in some cases they disappear and reappear;
3. if, like other coronoviruses, C-19 reinfection can occur - there are reports again today from South Korea on this;
4. due to the above, even if a super sensitive antibody test can be mass manufacturered what the results would mean.
Net result - all we can be certain of is an antigen test (approved by WHO) that shows if a traveler, student or employee has live virus on the day the swab is taken. It's not what the world wants nor needs but where the science is at. And this relies heavily on NCYT.