FWIW, I’ve been fully vaccinated (Moderna) since March. I was just in Provincetown, MA for the usual yearly 4th of July celebration with 10K other gay men, and Delta ripped through everyone. I got breakthrough COVID, which I assume is Delta because the symptoms were much more like the common cold than classic COVID. I probably know ~150 people in that group, and at least 14 people I know got breakthrough COVID. Meanwhile back here in LA I found another 5 people (trainers and members) in my very small, outdoor gym got breakthrough COVID. Everyone I know is fine health wise, no hospitalizations, and it was more annoying than anything, but it does indicate anecdotally that Delta is not going to go well.