That's normal. Diseases act as parasites on their hosts and its not in the best interest of a parasite to kill its host, or at least not quickly. That's what

That's normal. Diseases act as parasites on their hosts and its not in the best interest of a parasite to kill its host, or at least not quickly. That's what tends to make zoonotic diseases so dangerous, they've calibrated themselves to exist in an equilibrium with a host animal population but when they transfer to humans that balance is out of whack and they either are immediately wiped out by the immune system or they tend to overdo it and kill the host. COVID-19 seems to have "gotten lucky" in that it found itself with, from its perspective, a thankfully low lethality allowing it to spread widely. This can apply to bacteria even more than viruses, see https://aeon.co/essays/when-bacteria-kill-us-it-s-more-accident-than-assassination https://aeon.co/essays/when-bacteria-kill-us-it-s-more-accid... EDIT: I should say, though, that you shouldn't expect that to happen quickly. The selective pressure for COVID-19 to become less lethal is far less than it was for, say, MERS.