Rabies continues to kill 59 000 people a year, with a vast majority of these occurring in Africa and Asia. The disease is preventable with rapid administration of post-exposure prophylaxis (PEP) after exposure, however many of those persons affected by rabies are faced with vaccine shortages or cost prohibitive prices for treatment. Many countries still use intramuscular vaccine PEP schedules, which require 4-5 vials of vaccine to complete a full course. This can cost up to US$100 in rabies-endemic countries. When the average daily income per person in these communities is US$1-2, this can place a huge financial burden on patients.

WHO promotes the use of intradermal administration of modern cell culture rabies vaccines (with a potency of >2.5IU per intramuscular dose) for PEP. Intradermal administration offers an equally safe and efficacious alternative to intramuscular vaccination. Intradermal vaccination reduces the volume of vaccine used by 60-80%, is less costly and has potential to mitigate vaccine shortages. It requires only 1–2 vials of vaccine to complete a full course of PEP. Cost effectiveness modelling shows that when compared with intramuscular vaccination schedules, intradermal schedules are cost effective and dose sparing in all settings, even if the number of new bite patients is as low as 5 per month.

Multiple studies have been performed demonstrating the efficacy of intradermal administration and intradermal PEP schedules have been successfully introduced to many countries throughout Asia and Africa. These include India, Pakistan, Nepal, Bangladesh, Philippines, Sri Lanka, Madagascar and the United Republic of Tanzania. In countries where intradermal administration is an approved route for PEP, vaccine manufacturers 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 (Weekly Epidemiological Record, 2018, 93:201-220) recommends a one week, 2 site intradermal PEP schedule with 0.1mL of vaccine injected on days 0, 3 and 7. If the patient has already been immunized against rabies, then this can be reduced to a 1-site intradermal injection of 0.1mL on days 0 and 3 (WHO Expert Consultation on Rabies, third report, TRS 1012, WHO 2018). This additional revision, the reduction of the PEP intradermal schedule to one week, further improves cost effectiveness, reduces the number of required clinic visits by patients and improves patient compliance.

Any WHO-recommended PEP regimen can be used for people with category II and category III exposures. In category III exposures rabies immunoglobulin should be administered in addition to vaccine and thorough washing with soap and water of all bite wounds and scratches should be done immediately. ( See Summary of Key Points; WHO Position Paper on Rabies Vaccine, February 2018). A change in route of administration or in vaccine product during a PEP course is acceptable if such a change is unavoidable to complete the course.

In adopting intradermal vaccine schedules, countries can mitigate vaccine shortages, improve treatment affordability and provide more equitable access to rabies PEP. With efforts already underway to reduce the global burden of rabies and eliminate dog mediated rabies deaths worldwide by 2030, the adoption of intradermal vaccine schedules can help make this goal a reality.