Unfortunately there are a number of tick-borne illnesses. Eg, Powassan virus is a viral infection that attacks the central nervous system (leading to encephalitis). It can be transmitted within hours or even just 15 minutes of tick attachment.

Another is Alpha Gal. It is a molecule carried in tick saliva that can cause serious allergies to red meat and even dairy. Because the molecule is in the saliva, it can be delivered immediately.