Re-priming over sanded primer
Nope, you need to re-prime.  

That's why care while sanding is a good idea, and that's also why it's very common to prime 2 or more coats.  Honestly it's almost inevitable to blow through the first coat on sanding; this is just you exposing the high spots. 

Leveling is one goal of priming; you're using the primer essentially as a filler to fill the low spots.  

As you get the surface more the way you want, switch to finer sandpaper and less pressure.