Covid-19: four fifths of cases are asymptomatic, China figures indicate:
https://www.bmj.com/content/369/bmj.m1375
British epidemiologist Tom Jefferson tells the BMJ, “The sample [evidence from China] is small, and more data will become available. Also, it’s not clear exactly how these cases were identified. But let’s just say they are generalisable. And even if they are 10% out, then this suggests the virus is everywhere. If—and I stress, if—the results are representative, then we have to ask, ‘What the hell are we locking down for?”
Tom Jefferson, is an epidemiologist at the Cochrane Acute Respiratory Infections (ARI) Group and writes for thebmjopinion.