It's hard...
The very existence of breakthrough cases are used by the sort of people who don't want the vaccine in a sort of "see, it doesn't even mean I won't get COVID!" sort of mindset.
But... We know [and have known] this about vaccines. Some people don't take well to them. They're not 100% and haven't been sold as being 100% effective.
That is WHY we ask everyone to get them... Because if 95% of America gets the vaccine and they're 95% effective, that puts us WELL above the herd immunity threshold where R0 <<<< 1.
It doesn't mean that COVID magically and immediately goes away, but it should mean that any local outbreaks will be small and not spread widely.
(Note: of course 94's point still holds... We need the rest of the world to do this too. Much like today we have incursions of things like measles from other nations that don't have our vaccine numbers--and those spread due to idiot anti-vaxxers here--we can't globally eradicate COVID unless the rest of the world has very high vaccination rates too. Otherwise we're probably still looking at annual boosters if the protection of the vaccine wanes too much over time.)