(CN) — As the Covid-19 death toll in the United States passes the grim milestone of 200,000, a mathematic analysis of U.S. cases shows that 31 states entered their second wave at the end of July — while 13 others were still in the first wave.
The notion of a second wave of the novel coronavirus, a phenomenon wherein a disease infects one group of people first, then infections appear to decrease but later increase in a different part of the population resulting in a second wave of infections, has been looming since the global pandemic began. And recently, there is speculation that a second wave is starting in Europe.
Some European countries are reporting a rapid rise in Covid-19 hospitalizations. Hospitalizations have