A functional vaccine is not a silver bullet.
Like many things in life, we are searching for the silver bullet to fix everything that has gone wrong or is going wrong. We spend our hours thinking, "If only we had ..."
Which brings me to the "Swiss Cheese" approach to fighting the coronavirus. I think "just a few people" will be thinking that, "Ah, if I eat swiss cheese, that is a good defense against getting the virus." Nope! This is an analogy or metaphor for how to fight the disease, via a layer of defenses. The concept being that each defensive layer has holes in it, but by layering the defenses you cover the holes in one with actions taken in another layer of the defense.
Today, we have all the other layers available to us to fight COVID-19. Social distance, wear a mask, avoid crowds, wash your hands, stay home if you are sick, don't touch your face with your hands, etc. The last layer of defense is a vaccine, which in itself will not be the silver bullet that crushes the virus.
Public messaging is mentioned in one of the layers of swiss cheese. I can see people once they get the vaccine abandoning their previous adherence to all the protective measures — because they think they don't have to do them any more.
Lastly, getting people to take the vaccine will be no easy matter. What QAnon theory might pop up about the vaccine?