The first sentence spells it out pretty explicitly: > New evidence has emerged from China indicating that the large majority of coronavirus infections do not r

The first sentence spells it out pretty explicitly: > New evidence has emerged from China indicating that the large majority of coronavirus infections do not result in symptoms. This is not far off from the figures I had preciously been seeing of 50-70% of people never developing symptoms. If this is antibody testing, then the people who test positive are already immune to the virus (there's the question of whether different mutations can result in repeated infections, but that's a bit of a tangent).