I want to stop an indesign created pdf from reading illustrator text from an image in the pdf??

I want to stop an indesign created pdf from reading illustrator text from an image in the pdf.

Accessibility - At work we create accessible pdfs these days. I often have to drop complex Illustrator images into an inDesign document, but I want the generated pdf to read the alt text that I provide and NOT read the text from the illustrator file. Is this possible without my current (annoying) practice of having to create a duplicate of every illustrator file and outline the text?