Some areas have a shortage of supplies needed for testing, like reagents, and are only testing serious hospital cases. Epidemiological studies of other viruses suggest that at least 1% of the population has the virus once community spread is detected. That suggests millions have it, most of whom are as of yet asymptomatic (but highly contagious).
As well they should. Every singe American should get tested, so the infected can be quarantined. Then the rest of the country can go back to normal. If only they would go to wartime production of tests, reagents, swabs, etc...
Yes, but only promising if hospitals can get their hands on it. Extreme shortages of meds and supplies are extant in many hospitals across the country. If we don't have the meds, it doesn't matter how promising they are.
If they would just get moving and build meds and needed medical supplies already.