Aw Shaddup
It's not much different than California where everything you buy has a label that says it might cause cancer. It's a statement to cover their a$$ and doesn't really mean squat. Every other vaccine throughout history has pretty much prevented transmission as well as prevented infection, there's no reason to believe this one is any different.
That CYA statement is what the anti-vaxxers took and ran with, screaming "it isn't a vaccine! It doesn't prevent transmission!". None of that was true, there hadn't been enough time for the studies to come in so they couldn't definitively say it prevented transmission. Logically anyone could see that it does.