The study cited was done in 2020, and the Delta wave shows 'jabbed' victims are now infectious, like the cruise liner with all-'jabbed' crew and passengers contracting CoVID. So much so the CDC changed rules, again, defining 'vaccinated' as only after 14 days; if you get CoVID within that period you are 'unvaccinated', even though you have the spikes in you.
if you get covid you get lots of spikes
the spike protein fragments in all the vaccines are inactive - they’re a car with no engine. An eyelash in the eye - meant to stimulate antibodies. With the exception of Novavax, which is the entire spike protein turned into a toaster.
Breakthroughs are mostly showing up in those 72 or older. So if you’re worried about them, social distance from seniors.
re: cruise ship - all but 1 of the cases were crew. That should tell you where the problem lies.