It turns out that CoVid -19 is still CoVid-2, so the antibody tests were (kind of) accurate. Now, the real problem with that study seems to be that people self-selected AND that they were mostly upper middle class suburbanites who were already more isolated than people who work in crowded workplaces. The other factor is that participants were disproportionately from the foothills south and west of Stanford - where people live on large properties, there's often only one worker in the household, and a significant amount of work done from home in the first place, as I understand it.
I don't have my links handy - I'll try to post them. I popped in to post this update:
Coronavirus: California hasn't flattened curve — yet
We aren't seeing linear expansion of cases in California, but yesterday we had a bump up, and statewide, cases are up 15% in one week. Good news for the Bay Area - only up by 3%.
But that's still up. The criticism of the IMHE model is that it shows cases going to zero everywhere, which is an artifact of their model - not reality. Cases are not going to go to zero any time soon unless this virus truly is seasonal. California's weather in no way resembles seasonal weather elsewhere, though. The data from Australia (where the virus took strong hold during their autumn) will be interesting. Will it go up in Australia winter? Why was it so virulent in the relatively mild winter climate of Lombardy and Tuscany?
Lots to learn. Anyway, Peony, I do have more links on the Santa Clara study. I forgot I posted that here, and it's too late to correct it. The "19" in CoVid-19 is just shorthand for CV-2-2019 (year of origin).
The overall criticism of the study also spins on whether it was sensitive to all the versions of CoVid-2-19. Here's an article showing the variations in this virus (all of them CoVid-2, known to most of us as CoVid-19):
SARS Coronavirus 2 – LOINC
So I stand corrected and now understand the terminology of that study. Presumably, any immunity to CV-2 is immunity to CV-19.
It's important to note that most of these quickie, non-FDA validated fingerstick antibody tests cannot discriminate at all between the 5 known coronaviruses that infect humans.
Better tests out there that are coming up for EUA by the FDA have more specificity for 3 of the 5 coronaviruses, so 2 coronaviruses are eliminated from the positive results. They are also far better validated, properly designed tests. However, they are still in short supply.
I do have some questions about cross-reacting antibodies as I have seen several local people who have had "positive" antibody tests but also spent substantial time in the mid-east in the military. I'm a bit worried that there may be cross-reactivity with antibodies not from the current SARS-Cov-2 virus.