WHO recommends the intradermal route for post-exposure prophylaxis in all places where rabies vaccines are in short supply
The cost of cell culture rabies vaccines for intramuscular administration limits their widespread use in many areas where dog rabies is prevalent and both availability and/or affordability of rabies biologicals are limited. WHO has been promoting the use of economical post-exposure prophylaxis (PEP) regimens administered by the intradermal route for many years where more than 80`% of the people exposed to rabies cannot afford intramuscular regimens costing between $40 and $50 and which represents an average of 40 days of wages in Africa and Asia.
Intradermal administration of these vaccines offers an equally safe and immunogenic alternative that requires only 1–2 vials of vaccine to complete a full course of PEP, thereby reducing the volume used and the direct cost of vaccine by at least 60% depending of the vaccine type compared with standard intramuscular vaccination. There is no evidence that intradermal administration requires vaccines with a potency higher than that recommended for intramuscularly administered rabies vaccines.
Intradermal regimens have been successfully introduced for PEP in developing countries, such as India, the Philippines, Sri Lanka and Thailand. In these countries the intradermal route has been endorsed by national health authorities and the vaccines used are explicitly authorized for the intradermal route. In countries where intradermal administration is an approved route for post-exposure prophylaxis, manufacturers of vaccines proven to be safe and efficacious by this route should be requested to state that their vaccine can be used intradermally. Proper delivery of the vaccine requires sufficient staff training to ensure correct storage, reconstitution and injection.
WHO in the recently published WHO position paper on rabies vaccines [pdf 281kb] (Ref:Weekly Epidemilogical Record, 2010, 85:309-320) recommends one intradermal post-exposure regimen safety and efficacy of which has been thoroughly evaluated .(WHO Expert Consultation on Rabies [pdf 772kb], first report, TRS 931, WHO 2005). The intradermal route for PEP and this regimen were first endorsed by SAGE (WHO Strategic Advisory Group of Experts on Immunization) in 2007. The 2-site regimen prescribes injection of 0.1 mL at 2 sites (1 in each of the deltoid and thigh) on days 0, 3, 7 and 28.
This regimen can be used for people with category II and category III exposures. In category III exposure rabies immunoglobulin should be administered in addition to vaccine. (See WHO Guidelines for Post-Exposure Prophylaxis [pdf 160kb]).