Summary: Thereâs nothing the Doctor can do for Jack.
The Doctor can feel what Rose has done, it’s as though a massive boulder has been dropped into the timestream, causing everything to divert around it, and even at this distance the sense of wrongness is so disorienting he can hardly bear it.
He was able to draw the energy of the Time Vortex out of Rose and into himself, she’ll be fine, but Jack… What’s done is done, there’s no way of reversing it; the vortex is too much a part of Jack now, and the Doctor is about to regenerate.