Re: a bit late in my book
Isn't it a shame that infected people don't have a sign on their foreheads ?
How exactly do you expect to have a before-the-fact warning if we don't have a tool that can trace infected people and warn those who have been in contact to get tested ?
When we all have and use this app, people will be able to have a reasonable assumption that the people they deal with are not infected. And when something shows up, the people who were in contact get tested and that clears who's infected and who's not. The rest of us go on with our lives.
This is not a game. There is no API we can call on to alert people to our infection status beforehand.