eh...given enough time and enough dead, herd immunity is feasible. We've had viruses killing humans for tens of thousands of years. You don't think a few of those have gone extinct? Hell, was smallpox killing many in Europe b4 it wiped the Indians out in the Americas? Was syphilis even a thing in the Americas before it started wiping out Europeans?
FWIW:
The human genome contains billions of pieces of information and around 22,000 genes, but not all of it is, strictly speaking, human. Eight percent of our DNA consists of remnants of ancient viruses, and another 40 percent is made up of repetitive strings of genetic letters that is also thought to have a viral origin.