The risk of Covid to vaccinated individuals in larger than infinitesimal.
It is GREATLY reduced compared to vaccinated.
But for example… there was an unvaccinated worker at a nursing home. He infected over a dozen vaccinated residents, and 1 of those vaccinated residents passed from Covid.
There have been well over 100 breakthrough deaths.
Now, if enough people are vaccinated, to the point where there is extremely limited community spread, then the risk becomes infinitesimal.
For illustration only: let’s say the risk of a vaccinated dying from Covid is 1/25,000 Covid exposures. (And the risk to an unvaccinated person is 1/2000 covid exposures).
Now imagine there is still massive community spread: so the vaccinated person still faces a dozen covid exposures per day… 5000 covid exposures per year. With 5000 exposures… and 1/25000 chance of dying each time, your risk of death is not infinitesimal.
Now imagine there is very limited community spread… so instead of a dozen Covid exposures per day, you face only 1 exposure per month. So in the course of a year… only about 12 Covid exposures.. and 1/25,000 chance of dying each of those 12 times… now the risk is infinitesimal.
point being: unvaccinated individuals do increase the risk for all. And if enough people go unvaccinated, it prevents the risk from becoming infinitesimal.