The antibody tests now are very sensitive and specific, but it appears that many people, particularly those who never had symptoms with the illness, have no detectable antibodies as soon as 8 wks after exposure.
So total infection rates may have been significantly higher in some areas than once thought, because we are using antibodies to estimate this. But that also, doesn't necessarily mean that you have no immunity, if you have no antibodies.
If you by now take every Trump joke seriously or any media report without some skepticism, then I can't help you...
County and state health departments determine testing protocols and contract tracing. Many areas are doing it many different ways with many potential flaws.
I get patients from two states daily. One state locked down, but who has closed down centrally offered testing to everyone interestingly vs. one state opened up but who is still doing centralized testing. So many population, infection rate, and medical resource factors are involved. Unless you are in those health department meetings, it is hard to know about all of these factors, and how much state politics may or may not be playing a roll.
Hospital admissions data or death rate data certainly lags some, but is probably a better guide than reported new positive tests, when states are now doing more antibody tests, which means positive tests can indicate an infection that occurred months earlier and not this week.
Also, who really cares if 50% of young people all get the infection tomorrow (it appears the average positive test age has decreased), since these people aren't filling hospitals.