Question
Prophylaxis of rabies.
Answer
Rabies prophylaxis combines wound management, active immunization (vaccine), and passive immunization (immunoglobulin), tailored to the WHO exposure category of the bite/contact.
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) — a critically important, often underemphasized first step that substantially reduces viral load at the inoculation site; suturing of the wound is generally avoided or delayed, as it can drive the virus deeper into tissue.
WHO exposure categories and management:
- Category I (touching/feeding animals, licks on intact skin) — no exposure; no prophylaxis needed.
- 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 bat) — wound care, vaccine PLUS Rabies Immunoglobulin (RIG).
Active immunization (vaccine): modern cell-culture-derived vaccines (e.g., human diploid cell vaccine, purified chick embryo cell vaccine) given intramuscularly or intradermally on a defined multi-dose schedule (e.g., days 0, 3, 7, 14, ± 28, depending on the regimen used) — stimulates the host’s own antibody response, though this takes about a week or more to develop.
Passive immunization (Rabies Immunoglobulin, RIG): given for Category III exposures to provide immediate neutralizing antibody at the wound site, bridging the gap before the patient’s own active immune response 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) where available, given a lower risk of hypersensitivity reactions with ERIG.
Pre-exposure prophylaxis: recommended for high-risk occupational groups (veterinarians, animal handlers, laboratory workers handling the virus) — a shortened vaccine schedule without RIG, since the aim is to prime rather than provide full post-exposure protection; still requires prompt booster doses (without RIG) if subsequently exposed.
General prevention: animal (particularly dog) vaccination programmes, responsible pet ownership, and public health education about avoiding contact with stray/wild animals.