Question
Post exposure Prophylaxis for Rabies.
Answer
Post-exposure prophylaxis (PEP) for rabies combines wound management, active immunization, and (where indicated) passive immunization, tailored to the WHO exposure category.
Step 1 — Wound management: immediate, thorough washing of the wound with soap and water for at least 15 minutes, followed by application of a virucidal agent (povidone-iodine or alcohol); suturing of the wound is generally avoided or delayed, as it can drive the virus deeper into tissue.
Step 2 — WHO exposure category assessment:
- Category I (touching/feeding animals, licks on intact skin) — no exposure; no PEP needed beyond reassurance/wound care if any.
- Category II (minor scratches/abrasions without bleeding, licks on broken skin) — wound care plus vaccine alone.
- Category III (transdermal bites/scratches, licks on mucous membranes, contact with bats) — wound care, vaccine PLUS Rabies Immunoglobulin (RIG).
Step 3 — Active immunization (vaccine): modern cell-culture-derived vaccines (HDCV, PCECV, PVRV) given intramuscularly (Essen regimen: days 0, 3, 7, 14, ±28) or, increasingly, by the cost-effective intradermal route (using a fraction of the intramuscular dose at multiple sites) — stimulates the patient’s own antibody response, though this takes about a week or more to develop.
Step 4 — Passive immunization (Rabies Immunoglobulin, RIG): given for Category III exposures to provide immediate neutralizing antibody at the wound site, bridging the gap before active immunity develops; as much of the calculated dose as anatomically feasible is infiltrated directly around and into the wound, with any remainder given intramuscularly at a distant site; human RIG (HRIG) is preferred over equine RIG (ERIG) given lower risk of hypersensitivity reactions.
Special considerations: previously vaccinated individuals (with a documented complete pre-exposure or post-exposure course) require only booster doses (2 doses, days 0 and 3) without RIG on re-exposure, since they already have primed immunological memory; category assessment and the decision to observe the biting animal (if a healthy domestic dog/cat that can be observed for 10 days) versus immediately commencing PEP depends on local epidemiology and the animal’s availability for observation.
General prevention: animal (dog) vaccination programmes and public health education, complementing individual PEP.