Hence the need to isolate the unvaccinated, to protect them so they don’t get these new breeds and don’t make new ones based on them that reinfect the larger population.
> and don’t make new ones based on them that reinfect the larger population
The new breeds made by the unvaccinated are necessarily less dangerous and virulent, just based on the relevant evolutionary pressures (the more dangerous breeds that make people bedridden don't spread).
The new breeds made by the vaccinated, on the other hand - those have zero evolutionary pressure to become less dangerous, and can just as easily become more so (someone with a mutation that would make an unvaccinated person bedridden feels no effect and spreads it everywhere they go).
If COVID becomes less deadly but more widespread, and becomes part of the yearly flu season, blame that on the unvaccinated. But if COVID mutates to become more deadly and resistant to vaccines, blame the vaccinated.
> The new breeds made by the unvaccinated are necessarily less dangerous and virulent,
This is not a given. The virus is known to mutate more in unvaccinated hosts and this can make either more contagious or more lethal variations. There would be an advantage to have a longer incubation period.
On the vaccinated the same things are beneficial - longer incubation periods and the ability to infect others who are vaccinated. With a lower viral load, there will be fewer variations in vaccinated hosts, translating into fewer differences from the baseline virus.
> The virus is known to mutate more in unvaccinated hosts and this can make either more contagious or more lethal variations.
Of course vaccinated and unvaccinated can produce largely the same mutations. But that's not the point.
As I said, it's the evolutionary pressure which is the problem. If two people, one vaccinated and one not, get the same mutation, then maybe it's a strain which is dangerous enough for the unvaccinated person to go be sick in bed for a week. (Yes, incubation period - but that's the same both ways so it doesn't change the probabilities.) In this case, then because the vaccine mitigates the symptoms, the vaccinated person can go on with their daily life while sick with that more dangerous strain.
The fact that both groups produce similar mutations isn't the point, it's that the people have different reactions to the virus which changes how the mutations are able to spread.
It's not that there's a lower viral load. It's that the vaccinated are transmitting at all which is the problem, because there's no pressure for them to go be sick in bed when they're carrying around a mutation which could kill someone.
