06-17-2021, 01:57 PM
pdq wrote:
Yup, as I’m sure PeterB knows, that’s the way evolution works. If there’s a way of increasing transmissibility, given enough time and coronaviruses in the wild, life will find a way, often repeatedly.
Increased pathogenicity doesn’t typically benefit the virus though, so we can hope that drift will make for a less deadly, albeit more contagious virus. But that’s just hope at this point.
What's really concerning to me is that they're already seeing the secondary mutations ("Delta plus", etc.) ... lending credence to my idea that the longer you give this virus to cook, the more likely we'll be seeing something where the vaccines are largely or wholly ineffective. This particular virus seems to mutate at a frequency a bit higher than you'd expect for a coronavirus. The fact that it's apparently independently developing the same mutations in separate strains, suggests that there is indeed a selection process going on with this virus.
As for pathogenicity -- from the virus perspective, increased transmissibility and pathogenicity are advantageous. The virus just wants to make more copies of itself, and increased pathogenicity generally means that you're doing exactly that. So long as the pathogenicity doesn't interfere with transmissibility, that you don't kill the host before you've had plenty of time to develop new mutations and transmit yourself to other hosts. Also, it occurs to me that there's a very good chance that someone infected with these variants might inadvertently pass to an animal host, and then mutate and pass back to a human host. Hasn't happened yet, so far as we know, but it's just a matter of time...