nonresistant

1. Not resistant, especially to a disease or an environmental factor, such as heat or moisture.
2. Submissively obedient.

adjective

Submitting without objection or resistance: acquiescent, passive, resigned, submissive. See resist/yield.

1. Not resistant, especially to a disease or an environmental factor, such as heat or moisture.
2. Submissively obedient.

The adjective has 2 meanings:

Meaning #1: (often followed by `to') likely to be affected with
  Synonyms: liable, nonimmune, unresistant

Meaning #2: offering no resistance