A nice middle ground as suggested would be some sort of sickness/effect applied to your char that requires some measure of effort to cure. In the mean time taking some sort of negative staffs/effect until you do cure it. Either by remove curse, cure disease, or something of that nature would mean there is actually some measure of concern about being bitten/scratched by them that once it set in you would be pressed to look for a way to cure it or have to suffer under the effects.