vaccine can possibly be ready in a couple of months. Unless they are getting ready to roll out some half-assed product, and just wait for serious side effects to pop up a month or so later.
But yes, no matter when a good vaccine is finally here, it will take a long, long time to produce the many millions of doses that will be needed. Then there's the logistics of actually administering the vaccine. I remember the mass immunizations for the Salk vaccine in 1955. I am not sure what the upper age limit was for those getting it. I've tried to research that on line, but I'm probably asking the question wrong. At least up to age 12, which was how old my older brother was at the time.
With this, essentially everyone is going to need it. I'll ignore the anti-vaxxers out there, but I do know that I personally will be slow to get it. For one thing, I can still stay relatively isolated and wear a mask whenever I go out. For another, I want to give it time for unexpected side effects and what-not.