Flask gives immunity to corrupted blood. But has reduced effect.

I have a flask which gives immunity to bleeding and Corrupted Blood. (of the Iguana).
But it also has a modifier which says ".. 25% reduced effect" (Rationed).

What is "reduced effect of immunity"?
Instead of 0 bleeding, I will have 0 (zero) bleeding?
(Zero times anything is zero.)
Or, something else?
(In other words, my immunity will be gone? I will have a "small Corrupted Blood"? What is "small Corrupted Blood"?)