Up-voted because this is a complex dynamic that many people seem to be unaware of, or fall victim to over-simplification when discussing. The scientific literature supports the fact that vaccination reduces symptoms and reduces duration and intensity of viral shedding - but immunity acquired through natural infection also has the same effect.

So many people talk about "vaccinated versus unvaccinated", but this dualistic framing is not conducive to scientifically accurate discussion. There are at least three groups of people to acknowledge:

A) vaccinated

B) immune via natural infection

C) immunologically naive (have never been exposed to the virus)

The A & B groups will have very similar characteristics in terms of individual risks and risks to others. Group C is what many people mean to refer to when they say "unvaccinated people spread COVID faster and with more frequency".