a key milestone for covid vaccinations, there is new scrutiny on the origins of the coronavirus. a report found several chinese researchers fell ill and were hospitalized in november of 2019. they don't know what the researchers were sick from and this is before cove id-19s know. i want to speak with visiting professor of george washington university. dr. nguyen is the author of "lifelines, a doctor's journey for public health" and david culver that reported extensively on the pandemic from china and wuhan. you studied the chinese health