After receiving a tick bite, jenny worries that she may have become infected with lyme disease. her doctor immediately orders a lyme titer, which comes back as negative. her doctor advises her to come back in three weeks and have the titer repeated. why? the initial titer may have been done so early in the infection that detectable levels of antibody were not yet present the laboratory may have made an error, but it is unlikely to make the same error twice the doctor will send the second titer to a different laboratory as a backup t cell stimulation is delayed during lyme disease incubation