Mara resists coomb spores

"I am impressed with Mara Jade's ability to resist the spores," he admitted.
"Everyone else you tested them on was dead or dying within a few weeks," Shok Tinoktin replied. "Most within a few days."
Nom Anor nodded. His coomb-spore formula had indeed proven wonderfully effective, breaking down the victim's molecular structure and causing horrible death in short order.
If only he could find a way to make the not-so-subtle shift from simple poison to disease, where the spores could become self-propagating, spreading on their own from being to being and thus infecting large populations.
Nom Anor sighed and scratched his head yet again. The spores- coomb, brollup, tegnest, and a dozen other varieties- were but a hobby, one that he had been able to insert into hit official duties in attempting to develop some method for easily killing the supercreatures, the Jedi Knights. Also, such alchemical work, if successful, could prove critical in Nom Anor's ascension to the rank of high prefect. But in those endeavors and aspirations, to date at least, it appeared as if he had failed, for Mara Jade Skywalker had somehow defeated the spores, or at least had held them at bay.
-New Jedi Order: Vector Prime