Post-Exposure Prophylaxis for Rabies in Children

Introduction to Post-Exposure Prophylaxis

• The American Academy of Pediatrics recommends that children who have not been previously vaccinated against rabies should receive 4 doses of rabies vaccine on days 0, 3, 7, and 14, combined with Human Rabies Immunoglobulin (HRIG) 20 IU/kg on day 0 1, 2

Wound Management

• Immediate wound cleaning with soap and water for 15 minutes is the most effective single step to prevent rabies 1, 2
• The Centers for Disease Control and Prevention (CDC) recommends that if available, wound irrigation with a virucidal agent such as povidone-iodine should be performed 2, 3
• Tetanus prophylaxis and antibiotics should be administered as indicated 2, 3
• Wounds should not be sutured if possible, unless for cosmetic reasons or high risk of bacterial infection 2, 3

Components of Post-Exposure Prophylaxis

Human Rabies Immunoglobulin (HRIG)

• The dose of HRIG is 20 IU/kg body weight, given only once on day 0 1, 2
• As much HRIG as possible should be infiltrated around and into the wound, if anatomically possible 1, 2
• The remaining volume of HRIG that cannot be infiltrated into the wound should be administered intramuscularly at a different site from the vaccine 1, 2
• HRIG can be given up to day 7 after the first dose of vaccine if not given on day 0 1, 2

Rabies Vaccine

• The vaccination schedule is 4 doses: on days 0, 3, 7, and 14 (day 0 is the day of the first dose, not the day of exposure) 1, 2
• The dose of vaccine is 1.0 mL per dose, administered intramuscularly 1, 2
• The World Health Organization (WHO) recommends that the vaccine should not be administered in the gluteal area because it results in an inadequate immune response 3, 1, 2

Special Considerations for Children

Children with Immunosuppression

• The CDC recommends a 5-dose schedule (on days 0, 3, 7, 14, and 28) with HRIG for immunocompromised children 1, 2
• Serologic testing 7-14 days after the last dose should be considered to ensure seroconversion 1, 4

Children Who Have Been Previously Vaccinated Against Rabies

• Only 2 doses of vaccine (on days 0 and 3) are needed 1, 2
• HRIG is not required 2

Timing of Post-Exposure Prophylaxis

• Post-exposure prophylaxis should be started as soon as possible after exposure, ideally within 24 hours 1
• However, post-exposure prophylaxis should still be given even if the exposure was recognized months later, because rabies is almost 100% fatal after clinical symptoms appear 1

Safety in Children

• Studies have shown that HRIG and rabies vaccine are safe and effective in pediatric patients 1, 2
• The majority of side effects are mild; no serious events, rabies infections, or deaths have been reported 1, 2

Important Warnings

• Wound cleaning should not be delayed - it is the most crucial step 2
• Vaccine should not be administered in the gluteal area - it results in a poor immune response 3, 1, 2
• The recommended dose of HRIG should not be exceeded - it can suppress active antibody production 3, 2

Rabies Post-Exposure Prophylaxis for New Category III Exposure After Day 7

Key Principles for Managing New Exposures

• The Centers for Disease Control and Prevention recommends that each exposure be treated independently, with RIG administered for new Category III exposures, even if they occur after Day 7 of the original PEP series 5, 6
• For patients who experience a new Category III exposure after starting PEP for a Category II exposure, RIG should be administered as part of full Category III prophylaxis, as this represents a new, separate exposure requiring immediate passive immunization 5, 6

Rationale for Administering RIG After Day 7

• The guideline statement that "RIG is not indicated beyond day 7" specifically refers to the same exposure episode, not to new exposures occurring after Day 7, as RIG can interfere with the active antibody response already underway from the initial exposure 5, 6, 7
• RIG can only be given up to Day 7 of the original PEP series because by that time, vaccine-induced antibodies are presumed to have developed from that initial exposure, but a new exposure requires immediate passive immunization to prevent viral entry into peripheral nerves 5, 6, 7

Recommended Management for New Category III Exposures

• The Centers for Disease Control and Prevention recommends immediate thorough wound cleansing with soap and water for 15 minutes, followed by povidone-iodine irrigation if available, for new Category III exposures 5, 6
• Administer RIG at 20 IU/kg body weight, infiltrating as much as anatomically feasible around and into the new wound(s), with any remaining volume given intramuscularly at a site distant from vaccine administration 5, 6
• Continue the vaccine series, completing the original 4-dose schedule (Days 0, 3, 7, 14) and considering additional doses depending on consultation with rabies experts 7, 8, 9

Critical Clinical Pitfalls to Avoid

• Do not withhold RIG based on the "no RIG after Day 7" rule when dealing with a new exposure, as this rule applies only to delayed administration of RIG for the same exposure, not to new exposures occurring after the initial PEP series has begun 5, 6

Special Considerations for Previously Vaccinated Status

• A patient is not yet considered "previously vaccinated" for purposes of a new exposure if they have only received a partial vaccine series, as "previously vaccinated" status requires completion of a full vaccine series (either pre-exposure or post-exposure) 5, 7, 8
• Full Category III prophylaxis with RIG is indicated for patients who have not completed a full vaccine series, even if they have received some doses, as they have not yet mounted a complete immune response 5, 6, 8