Comparison of safety and immunogenicity of 2 WHO prequalified rabies vaccines administered by one week, 4 site intra dermal regimen (4-4-4-0-0) in animal bite cases

Abstract

The currently advocated rabies post-exposure prophylaxis regimens are of one month duration with reduced patient compliance. WHO recommended research on shortened vaccination regimens which have a practical and economic advantage over the existing regimens. Hence, the present study was undertaken to assess the safety and immunogenicity of 2 WHO prequalified rabies vaccines administered by one week, 4 site intra dermal regimen (4-4-4-0-0) in animal bite cases. This study was a comparative, open label, phase III, randomized clinical trial conducted at Anti rabies clinic, KIMS Hospital, Bangalore, India. The study was registered in Clinical Trials Registry of India (CTRI) bearing the registration number CTRI/2012/12/003230. Ninety subjects with category II/III animal bites/exposures were enrolled. Equine rabies immunoglobulin was administered to all category III exposures. 0.1 mL of either purified chick embryo cell vaccine (Rabipur) or purified verocell rabies vaccine (Verorab) was administered intradermally into 4 sites on days 0, 3 and 7 to all the study subjects. Serum of subjects collected on day 0, 14, 90 and 365 were analyzed for rabies virus neutralizing antibody (RVNA) concentration. The incidence of ADR in Rabipur and Verorab group was 2.96% and 1.14% respectively. In Rabipur group, geometric mean concentration (95% confidence interval) of RVNA was 14.5 (13.50, 15.57), 11.78 (11.27, 12.31) and 5.95 (5.50, 6.44) IU/mL on days 14, 90 and 365 respectively; In Verorab group geometric mean concentration (95% confidence interval) of RVNA was 14.43 (13.41, 15.53), 11.93 (11.47, 12.40) and 5.67 (5.29, 6.08) IU/mL on days 14, 90 and 365 respectively. In conclusion, Rabipur and Verorab were found to be safe, immunogenic and comparable with each other, when administered using one week, 4 site intradermal regimen (4-4-4-0-0) in animal bite cases.