Concerning human prophylaxis, an additional challenge is the lack of or limited availability and accessibility of human biologics for PEP, a reoccurring problem in many poorly resourced countries. These products should be provided free or at a subsidized price by the health care system, but in many places they are sold by government-owned and private clinics at a cost, which is often beyond the financial means of animal bite victims. The full cost of PEP alone (direct costs of vaccine and RIG range between $40 to $75, depending on country and product used [18] ) as well as additional costs (medical fees, transportation to hospital, accommodation, and income loss) can easily represent several months of a rural family revenue [18, 29] . Rabies biologics costs have been decreasing gradually mostly due to a more competitive market, with new vaccines and RIG being produced by manufacturers based in emerging economies (particularly in India and China). Although only a small number of vaccines are currently prequalified by WHO, more emerging products should fulfill WHO requirements and obtain this recognition, increasing market competition and further reducing costs. However, any increase in the availability of additional products must be balanced against the risk of biologics having poor quality [81] or counterfeit origins by greater regulatory scrutiny. To assist dog-bite victims and governments struggling to provide adequate quantities of rabies biologics locally, WHO has been promoting the use of the intradermal route for PEP, which provides a reduction by 60 to 80% of the vaccine needed for one PEP regimen [82] . Adoption of the intradermal route should be further encouraged [83] . Furthermore, research on new products, especially cocktails of monoclonal antibodies [84] to replace human and equine RIG, improved vaccines, reduced PEP regimens, and intradermal delivery devices should be a priority [59] .