Side-by-side Comparative Study of the Immunogenicity of the Intramuscular and Intradermal Rabies Post-exposure Prophylaxis Regimens in a Cohort of Suspected Rabies Virus (RABV) Exposed Individuals

A 1-week intradermal regimen of rabies post-exposure prophylaxis induces a similar antibody and T cell response as the standard 2-week intramuscular regimen. The shortened intradermal (ID) regimen saves vaccine doses, costs, and treatment time. All World Health Organization (WHO) pre-qualified rabies vaccines for humans are inactivated tissue culture rabies virus formulations produced for intramuscular (IM) administration. Due to costs and vaccine shortage, dose-saving intradermal (ID) administration of rabies post-exposure prophylaxis (PEP) is encouraged by WHO. This study compared the immunogenicity of the ID 2-site, 3-visit Institut Pasteur Cambodge (IPC) PEP regimen to the IM 1-site, 4-visit 4-dose Essen regimen using Verorab vaccine (Sanofi). The development of neutralizing antibodies (nAbs) and T cell response was assessed in 210 patients with a category II or III animal exposure in a rabies-endemic country. At day 28, all participants developed nAbs (& GE;0.5 IU/mL), irrespective of PEP scheme, age, or administration of rabies immunoglobulin. T cell response and nAb titers were similar for both PEP schemes. This study demonstrated that the 1-week ID IPC regimen is as effective as the 2-week IM 4-dose Essen regimen in inducing an anti-rabies immune response under real-life PEP.

Automated summary

A 1-week intradermal regimen of rabies post-exposure prophylaxis induces a similar antibody and T cell response as the standard 2-week intramuscular regimen. The shortened intradermal (ID) regimen saves vaccine doses, costs, and treatment time. Due to costs and vaccine shortage, dose-saving intradermal (ID) administration of rabies post-exposure prophylaxis (PEP) is encouraged by WHO.