It's more contagious precisely because of the long incubation rate and the fact that it's symptoms, in the majority of cases are either mild or not there at all. This is, of course, ignoring the fact that Viruses tend to get less deadly as they mutate person to person. The milder strains win out over the stronger ones, becuase a virus evolves to bind to a living host.
The original plan of Borris' and Trumps for herd immunity was the right strategy I'm afraid.
As for Africa, It sucks to say it but people, politicians, the world at large won't really care. They have far more risky diseases than Corona, however.