PDF with Linework Does Not Vectorize

Is the PDF in question customer provided artwork?

It is still very common for many computer users to not know the difference between vector-based artwork and pixel-based artwork. We see this scenario at my work place all the time: a client will email us their logo or some other kind of graphical item as a pixel-based image in JPEG or PNG format. Such files can't be used in a lot of our work projects since computer driven routing tables and vinyl cutters will only "see" vector outline shapes. So we ask them if they have vector-based versions of their art files. They can email files in Illustrator AI format, EPS, PDF, etc. Very often the client will merely place that same JPEG image on a page in MS Word or some other app and export the document as a PDF -and then email it to us. Yeah, that trick does not work. Some customers get a bit put off when we tell them their PDF file didn't contain any vector objects, "can't you just use the file? It's digital after all." We give them an option of re-creating their logo in vector form, but we don't do that work for free and the re-creation of their logo may not be absolutely accurate compared to the original either. Most of the time the client finds the right kind of artwork and sends it to us (especially if the art is from a large company).

Lauren,

I believe, as do Doug and Ton I believe, that your PDF is just an image; a PDF can be purely vector or raster and any combination of those.

"The linework is not vectorizing for me."

I am afraid you will have to create the vector artwork anew, unless you can get back to the original vector source, which is the real/best solution if possible.

With linework, the least worst way is to redraw with the suitable tool(s), Pen, Line Segment, Rectangle, Ellipse, whichever relevant.

A worse way is to use Image Trace which will give inferior results.

Have a look at releasing clipping paths. Or maybe it is an image?

What is the source of the PDF?