There are lots of covid infections where the person develops no symptoms but gets organ damage or long covid anyway, if that is what you mean about no COVID.

There are lots of covid infections where the person develops no symptoms but gets organ damage or long covid anyway, if that is what you mean about no COVID. Test positive = you have COVID, even if no symptoms. No symptoms and no test = you might or might not have COVID. It might be possible to detect virus reservoirs in people after the infection itself resolves, though.