Nothing like that has been proven; the opposite is closer to the truth. Maybe you just mean "have been proven not to effectively halt transmission"?
Primary immunization with two doses of ChAdOx1 nCoV-19 or BNT162b2 vaccine provided limited protection against symptomatic disease caused by the omicron variant. A BNT162b2 or mRNA-1273 booster after either the ChAdOx1 nCoV-19 or BNT162b2 primary course substantially increased protection, but that protection waned over time. (Funded by the U.K. Health Security Agency.
Don’t get me wrong they oversold the vax. But what I quoted are the key words here. If Trump’s vaccines turn COVID into a literal cold for all but the most compromised of individuals… it works.