Pre-exposure studies with purified chick embryo cell culture rabies vaccine and human diploid cell vaccine: serological and clinical responses in man.
Clinical reactions and neutralizing antibody responses to six pre-exposure regimens of purified chick embryo cell culture rabies vaccine (PCECV) and human diploid cell strain rabies vaccine (HDCSV) were studied in 177 volunteers. Antibody kinetics, height of the response and persistence of antibody over two years were virtually identical after PCECV and HDCSV. An antibody response was detected in all subjects on day 14 when the highest titres were found after two intramuscular (i.m.) 1.0 ml doses of a schedule of immunization on days 0, 7 and 21. In comparison, a schedule of immunization on days 0, 28 and 56 ultimately evoked the highest titres 21 days after the final injection, but antibody persisted equally well over two years with either schedule. Neutralizing antibody titres were lower after intradermal (i.d.) vaccination with 0.1 ml compared to 1.0 ml i.m. on days 0, 7 and 21, but when given on days 0, 28 and 56 the responses were comparable. Three subjects with a personal or family history of atopy developed urticarial lesions after PCECV. Both vaccines were otherwise well tolerated.