Quote:
Originally Posted by pstinard  I'm on it. Here is one research article that says that antibody titers are NOT sufficient to indicate rabies immunity: http://www.pnas.org/content/83/20/7947.full.pdf
"This study also shows that a minimum virus-neutralizing antibody titer is not widely applicable as an indication of adequate animal vaccination, especially in wildlife species, unlike the arbitrarily defined level of 0.5 unit/ml in humans, which is considered indicative of successful rabies immunization (22). As an illustration, raccoon 40 had a virus-neutralizing antibody titer of 1.3 units/ml at the time of challenge but died following inoculation with rabies virus, whereas raccoons 56 and 57 survived challenge with virus-neutralizing antibody titers of 0.6 unit/ml. Other raccoons, immunized i.m. or orally with V-RG, or parenterally with live ERA RV 194-2 virus, died following rabies inoculation despite titers in the range of 0.6-9.0 units/ml on the day of challenge (C.E.R., unpublished data). Clearly, virus-neutralizing antibody titer alone is unsuitable as the sole criterion of successful rabies immunization. A protective index may be defined for a particular study, but other factors besides specific humoral responses are important in host defense against rabies (23). It remains uncertain whether a minimum virus-neutralizing antibody titer can be correlated with protection." |
And this is why I always say titering is mostly just a total waste of money. All it measures is humoral immunity - it does NOT measure cell-mediated immunity.
You can have a positive titer, but not have celll-mediated immunity and therefore cannot fight the disease -or- you can have a negative titer, but have cell-mediated immunity and will be able to fight the disease. So there is really no point in knowing the status of humoral immunity since it means almost nothing.