Immunizing rhymes with:
unionizing, antagonizing, dehumanizing, demonizing, galvanizing, harmonizing, hellenizing, humanizing, ionizing, organizing, patronizing, reorganizing, revolutionizing, scrutinizing, synchronizing, unionizing, womanizing
Immunizing sounds like:
imagines, imaging, imagining, inasmuch, incense, inching, incisions, incomes, incoming, ingenious, ingenuous, innocence, inocencio, insomniac, insouciance, ionizing