Human rabies globulin and human diploid vaccine dose determinations

Veterinary students were injected with either human rabies immune globulin and human diploid rabies vaccine, or with human diploid vaccine alone. All those students who received three or more doses of the vaccine developed high levels of neutralizing antibodies by the rapid fluorescent focus inhibition test (RFFIT). The levels of early antibody in the students receiving the combination of globulin and vaccine depended very much on the dose of globulin. The neutralizing antibody levels in the sera of students who received 12 IU/kg were low 48 hours after the globulin injection: 6 of the 25 students receiving this dose were found to have no antibody, and eight were found to have titers between 1:6 and 1:10. When the globulin dose of 20 or 30 IU/kg was administered all students had early titers of 1:11 or above and all students subsequently developed high levels of antibody.