Does a Successful Save vs.Disease protect you until the next day?

So you have a monster that can inflict an Injury Track disease. The PC successfully saves to avoid contracting the disease when he is injured in the first round of combat. If he is injured in the same way by the same creature in the 2nd round, does he need to save again or is he "immune" for the rest of the combat and/or day? I can’t find where the RAW addresses this…