What is the recommended rabies vaccine schedule for a patient exposed to a potentially rabid animal, considering prior vaccination history, severity of exposure, and local health guidelines?

Rabies Post-Exposure Prophylaxis Schedule

Standard Regimen for Previously Unvaccinated Persons

For individuals never vaccinated against rabies who are exposed, administer 4 doses of rabies vaccine (HDCV or PCECV) intramuscularly on days 0,3,7, and 14, combined with human rabies immune globulin (HRIG) at 20 IU/kg on day 0. 1

Immediate Wound Management

• Thoroughly wash all wounds with soap and water for 15 minutes immediately—this single intervention is perhaps the most effective measure for preventing rabies infection. 1
• Follow with irrigation using a virucidal agent such as povidone-iodine solution if available. 2, 1

Vaccine Administration Details

• Administer 1.0 mL per dose intramuscularly on days 0,3,7, and 14 (day 0 is the day the first dose is given, not necessarily the exposure date). 1
• Inject in the deltoid muscle for adults and older children; use the anterolateral thigh for young children. 1
• Never use the gluteal area for vaccine administration—this produces inadequate antibody response and is associated with vaccine failures. 1, 3

HRIG Administration Protocol

• Administer HRIG at exactly 20 IU/kg body weight on day 0, ideally simultaneously with the first vaccine dose. 1, 3
• Infiltrate the full calculated dose around and into the wound(s) if anatomically feasible; inject any remaining volume intramuscularly at a site distant from vaccine administration. 2, 1, 3
• HRIG should never be administered in the same syringe or at the same anatomical site as the vaccine. 2, 1, 3
• Do not exceed 20 IU/kg—higher doses suppress active antibody production. 2, 1
• If HRIG was not given on day 0, it can still be administered up to and including day 7 of the vaccine series, but not beyond day 7. 2, 4

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Modified Regimen for Previously Vaccinated Persons

Previously vaccinated individuals require only 2 doses of vaccine on days 0 and 3, and do NOT receive HRIG. 1, 5

• This applies to anyone who has completed a recommended pre-exposure or post-exposure vaccination series with a cell culture vaccine and has documented antibody response. 2, 1
• Giving HRIG to previously vaccinated persons is a critical error that suppresses the memory immune response. 1, 4

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Special Population: Immunocompromised Patients

Immunocompromised patients require a 5-dose vaccine regimen on days 0,3,7,14, and 28, plus HRIG at 20 IU/kg on day 0, even if previously vaccinated. 1, 5

Conditions Requiring 5-Dose Regimen

• Corticosteroid use, other immunosuppressive agents, antimalarials, HIV infection, chronic lymphoproliferative leukemia, or other immunosuppressive illnesses. 1

Mandatory Serologic Testing

• One or more serum samples must be tested for rabies virus-neutralizing antibody by rapid fluorescent focus inhibition test (RFFIT) 1-2 weeks after the final vaccine dose. 1
• An acceptable antibody response is complete neutralization of challenge virus at a 1:5 serum dilution. 1
• If no acceptable antibody response is detected, manage in consultation with the patient's physician and public health officials. 1

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Timing Considerations

Initiate post-exposure prophylaxis as soon as possible after exposure, ideally within 24 hours, but treatment remains indicated even if weeks or months have elapsed since exposure. 1

• There is no absolute cutoff for initiating prophylaxis—rabies incubation periods can exceed one year and the disease is uniformly fatal once symptoms appear. 1
• Delays of a few days for individual doses are unimportant and do not compromise protection. 4
• For longer interruptions (weeks or more), do not restart the series—resume from where you left off and obtain serologic testing 7-14 days after the final dose to confirm adequate response. 1, 4

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Pediatric Considerations

Children receive the same vaccine dose volume (1.0 mL) and HRIG dose (20 IU/kg) as adults. 1, 5

• For young children, administer vaccine in the anterolateral thigh rather than the deltoid. 1, 3
• The same 4-dose schedule applies to all age groups, including infants. 1

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Common Critical Pitfalls to Avoid

• Never administer vaccine in the gluteal area—this is associated with vaccine failure. 1, 3
• Never give HRIG to previously vaccinated persons—it inhibits the anamnestic response. 1, 4
• Never exceed 20 IU/kg of HRIG—higher doses suppress active antibody production. 2, 1
• Never administer HRIG after day 7 of the vaccine series—it may suppress active antibody production at that point. 2, 4
• Never restart the vaccine series for missed doses—resume from where you left off. 4
• Never withhold treatment while waiting for animal observation results in rabies-endemic areas—treatment can be discontinued if the animal remains healthy after 10 days. 1, 3

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Efficacy

When administered promptly and appropriately, rabies post-exposure prophylaxis combining wound care, HRIG infiltration, and the vaccine series is nearly 100% effective in preventing human rabies. 1, 5

• No failures have been documented in the United States since current biologics have been licensed, despite not all prophylaxis being properly administered. 2
• Post-vaccination serologic testing is not necessary in immunocompetent individuals, as all healthy persons demonstrate adequate antibody response when prophylaxis is administered according to guidelines. 5