Pre-exposure prophylaxis in Peace Corps volunteers with intradermal human diploid cell rabies vaccine

The Peace Corps has had approximately 60 000 person/years of experience with rabies pre-exposure duck embryo vaccine (DEV) immunizations, which are required in 80% of volunteer assignments. Rabies exposure treatment rate is much higher in these areas than in the United States. One death from rabies has occurred despite pre-exposure injections. One death also occurred from serum hepatitis contracted in local emergency management of an anaphylactic reaction to duck embryo vaccine. A query to the Peace Corps field medical offices obtained reports of 21 serious reactions in approximately 8000 duck embryo immunizations. Two thirds of the reactions occurred with the first injection. Only a third of titres measured after four injections of DEV achieved a protective level of greater than or equal to 1:16. Because of these problems human diploid intracellular vaccine (HDCV) was studied in areas where it was available. Because of the high cost and initial short supply, intradermal injections of 0.1 ml HDCV were given. 567 of 570 persons achieved adequate titres. No systemic reactions were reported with intradermal HDCV.