Why wouldn't you just have the vulnerable adults get vaccinated? At what point will done of these people just start vaccinating in the womb or just treat it lik

Why wouldn't you just have the vulnerable adults get vaccinated? At what point will done of these people just start vaccinating in the womb or just treat it like circumcision? Circumcision is not needed but might as well just poke babies with needles immediately after their born to make sure we traumatize them as much as possible.