I think we can conservatively say that we've had 3 times as many cases as reported. I think the number is higher than that, but let's say it's 3.
25,600,000 reported cases => 76,800,000 actual cases. Combine that with (coincidentally) 25,600,000 vaccinations and we have 102,400,000 with some sort of immunity.
We're truly getting there. If we can hit that 100,000,000 shot target, I'd say we're home free.