Pre-exposure purified vero cell rabies vaccine and concomitant routine childhood vaccinations: 5-year post-vaccination follow-up study of an infant cohort in Vietnam.

Children have a high risk of exposure to rabies in countries where the disease is endemic. This prospective, 5-year study followed two groups of children who had received diphtheria, tetanus, whole-cell pertussis and inactivated poliomyelitis vaccine (DTP-IPV) at 2, 3, 4 months and 1 year (Group B) or concomitant with three doses of purified Vero cell rabies vaccine (PVRV), given at 2, 4 months and 1 year (Group A). Antibody determinations were made annually for 5 years. Data were available from a total of 72 subjects; 30 in Group A and 32 in Group B. In Group A, the percentage of patients immunized against rabies (anti-rabies > or = 0.5 IU/ml) decreased from 100% after the third vaccination to 63%, 5 years later. After 5 years, 93.8% in Group A and 96.7% in Group B had seroprotective diphtheria antibody titers > or = 0.01 IU/ml, and all subjects had anti-polio (type 1, 2 and 3) seroprotective titers > or = 5 1:dil. We conclude that co-administration of PVRV with DTP-IPV elicited protective antibody concentrations to all antigens that persist for at least 5 years, with continued protection against rabies in over 60% of subjects. These results are consistent with integration of pre-exposure rabies vaccination into the Expanded Program on Immunization (EPI) in countries where rabies is endemic.