Here is something I did not expect, from  NBC News : A majority of people in the U.S have had Covid-19 at least once — likely more than 70% of the country , White House Covid-19 Response Coordinator Ashish Jha said on Thursday, citing data from the Centers for Disease Control and Prevention. Many have been infected multiple times.   Let me do some math.  So far, the U.S. has had a little more than  92 million COVID-19 cases.   Our population is 335 million, so I calculated 28%, which is far lower than the 70% cited by Dr. Jha. But the  World Health Organization  reported in April that up to 65% of Africans have been infected by SARS-CoV-2.  If this is true, the continent had 97 times more cases than reported!!! Further, the global average should be 16 times higher! There is no mention of how asymptomaticity factored into the above. So if you multiply the actual covid cases by 16, that would mean that the average person in the USA actually was infected more than  four times each .   Tha