Comparison of Safety and Immunogenicity of PVRV and PCECV Immunized in Patients with WHO Category II Animal Exposure: A Study Based on Different Age Groups

BACKGROUND The aim of this study was to compare the safety and immunogenicity between purified vero cell rabies vaccine (PVRV) and purified chick embryo cell vaccine (PCECV) in patients with WHO category II animal exposure, especially in different age groups. METHODOLOGY/PRINCIPAL FINDINGS In one-year clinical observation after vaccination with PVRV or PCECV under Zagreb (2-1-1) or Essen (1-1-1-1-1) regimens, information collection for the demographic and adverse events (AEs) and rabies virus laboratory examination of neutralizing antibody (RVNA) titers were performed for all patients with WHO category II animal exposure in Wuhan city. The results showed no significant differences of safety and immunogenicity between PVRV and PCECV both in Zagreb and Essen regimens. However, when compared with other age groups, most systemic AEs (36/61) occurred in <5-year-old patients, and <5-year-old patients have significant lower RVNA titer and seroconversion rate (RVNA ≥0.5 IU/ml) at day 7 both in Zagreb and Essen regimens or PVRV and PCECV groups. CONCLUSIONS Our data showed that vaccination with PVRV is as safe and immunogenic as PCECV in patients of all age groups, but might be more popular for clinical use. When performing a vaccination with rabies vaccine in young children, the most optimal vaccine regimen should be selected.