It could be that this particular virus has an enzyme that recognizes and incorporates other viral nucleic acid and incorporates the alien viral nucleic acid with it's own. In this way, whenever the virus ran into another different virus, the chance for mutation would be very high. Many times this would result in a deletrious mutation(s) in the viral genome, but it would only take one newly mutated and functioning virus to make a million.
How that for tin foil on this day, april 24 :-)
"It could be that this particular virus has an enzyme that recognizes and incorporates other viral nucleic acid and incorporates the alien viral nucleic acid with it's own."
satellite nucleic acids....someone else on FR at the very begining of this outbreak brought that possibility up.