I almost hesitate to bring this up, especially with the PSF Covid thread locked, but what should we infer from all of the in-team outbreaks in the NFL and other sports? If we assume that the vast majority of these athletes are vaccinated, that would suggest not just that there are breakthrough infections, but that vaccinated people are infecting other vaccinated people.
I can imagine certain posters will say this shows the vaccines are and always have been ####e, and hey, maybe that's the answer. It could also mean that Omicron really has achieved a level of vaccine breakthrough (although of course we don't know if all these infections even are from the new variant).
One factor I haven't heard discussed much: What if it reflects that many athletes got the one-shot J&J vax, so they are far more likely to get breakthroughs now? I can certainly see why that decision would have made sense; the messaging at the time was that all three vaccines provided roughly equal levels of protection, so I can imagine many athletes figured they were young and in excellent health, so why not do the minimum necessary to check the box.
Anyway, I'm mostly just noodling. I don't have any expertise in this stuff (but I would certainly love to hear what some of those who do have expertise think of my theory).