Absolutely not.

Just because both *can* spread COVID doesn't mean "it's the same." Absolutely not.

First of all, the vaccinated get breakthroughs at a fraction of the rate of the unvaccinated. Just look at those hospitalized for COVID, and the vaccinated is a small fraction of the total. SO.... if they're getting sick much less often, then they are contagious much less often.

Secondly, the number of days a vaccinated breakthrough infection is contagious is only a few days, wherein for someone not vaccinated, it's over a week.

So, let's say the more contagious Delta Variant has an R0 of 1.5. Now consider this scenario: a convention of 10,000 unvaccinated people begins with 10 infected people. The first day, they infect 15 more. On day two, the 25 infected people infect 37 more people. On day three, the 62 infected people infect 93 more people. And so on... The infection will explode in this superspreader event.

Now consider another scenario: there's another convention of 10,000 people who are all vaccinated. Ten of them show up infected with COVID. But, in the vaccinated population, the R0 is a fraction of what it is for the unvaccinated... let's say it's 0.15. So, the first day, the ten infected will infect at most 2 people. On day two, the 12 infected infect another 2. On day three, the 14 infected infect another 2. On day four, there are now only 6 infected people, because the first 10 are no longer infected BECAUSE THEY WERE VACCINATED. In a few more days, COVID will be eliminated from the convention of the vaccinated.

So... they don't spread it just the same.