Reduced dose pre-exposure primary and booster intradermal rabies vaccination with a purified chick embryo cell vaccine (PCECV) is immunogenic and safe in adults

Pre-exposure vaccination of persons at risk with intradermally administered reduced dose cell culture rabies vaccines remains controversial in low-enzootic countries. In a prospective clinical trial of adult volunteers (N = 25), we studied the immune response to purified chick embryo cell vaccine (PCECV) administered intradermally at a reduced dose (0.1 mL) in a three-dose schedule (0, 7 and 21 days). In 10 subjects, immunogenicity of intradermally administered one-dose booster vaccination with 0.1 mL PCECV was investigated. All participants were seroconverted 3 weeks after primary and 1 week after booster vaccination (antibody titre ≥0.5 EU/mL, measured by enzyme linked immunosorbent assay). Local adverse events such as erythema and swelling were moderate and transitory. The intradermal vaccination route offers an efficacious and cost-reducing strategy to increase the accessibility of cell culture rabies vaccines.