Chicks hatched early, some still unhatched, should I go ahead and give mareks shot?

[Brandi86]

I had one chick that hatched last night on day 19, some hatched today, I can hear some chirping in the incubator so I know I probably have a few more on the way, but I only have one vile of mareks vaccination. Should I go ahead and vaccinate the ones that have hatched? That means the other ones that haven't hatched out yet won't be vaccinated, or should I just wait for the others to hatch out?

This is my first time hatching and I'm not sure what to do.