Is ERIG (Equine Rabies Immune Globulin) ever given to a patient previously vaccinated for rabies, regardless of time elapsed since the last vaccine dose?

ERIG/RIG is Never Given to Previously Vaccinated Patients

If a patient has ever received a complete rabies vaccination series (either pre-exposure or post-exposure), they should receive only vaccine doses and absolutely no rabies immune globulin (RIG/ERIG), regardless of how much time has elapsed since their last vaccination. 1, 2

Why RIG is Contraindicated in Previously Vaccinated Persons

• Previously vaccinated individuals maintain immunological memory and mount a rapid anamnestic (recall) antibody response upon re-vaccination, typically by day 7. 2

• Administration of passive antibody (RIG/ERIG) can actually suppress or inhibit the strength and rapidity of this expected anamnestic response, which is counterproductive. 1, 2

• The CDC explicitly states that "administration of RIG is unnecessary and should not be administered to previously vaccinated persons because the administration of passive antibody might inhibit the relative strength or rapidity of an expected anamnestic response." 1

Correct Post-Exposure Protocol for Previously Vaccinated Patients

Immediate Wound Management

• Thoroughly wash and flush all wounds with soap and copious water for approximately 15 minutes. 2, 3

• Apply povidone-iodine solution or similar virucidal agent to the wound site. 2, 3

• Avoid suturing when possible to prevent deeper viral inoculation. 2

• Administer tetanus prophylaxis if indicated. 2

Vaccination Schedule Only

• Administer only 2 doses of rabies vaccine (1.0 mL each, intramuscularly in the deltoid): one immediately (day 0) and one on day 3. 1, 2, 4

• Do NOT administer the 5-dose schedule used for unvaccinated persons. 2

• Do NOT administer any RIG/ERIG under any circumstances. 1, 2, 4

Definition of "Previously Vaccinated"

A person is considered previously vaccinated if they have received: 1

• Any complete pre-exposure vaccination series (typically 3 doses) with a cell culture vaccine (HDCV, PCECV, or RVA), OR

• Any complete post-exposure prophylaxis series (5 doses) with a cell culture vaccine, OR

• Any other vaccine regimen with documented rabies virus neutralizing antibody titer

Time Elapsed Does Not Matter

• The simplified 2-dose protocol without RIG applies regardless of whether the previous vaccination was 1 year ago, 10 years ago, or even decades ago. 2

• Studies demonstrate that previously vaccinated individuals maintain immunological memory even decades after initial vaccination, with the majority showing anamnestic responses by day 7. 2

• No minimum antibody titer is required before exposure to qualify for this simplified regimen—the history of complete vaccination alone is sufficient. 1

Critical Exception: Immunocompromised Patients

• If the patient is immunocompromised (by disease or medications), they require the full 5-dose vaccine schedule (days 0,3,7,14,28) even with prior vaccination history. 2, 4

• Serologic testing should be performed to confirm adequate antibody response in immunosuppressed patients. 2, 4

• However, even immunocompromised previously vaccinated patients do NOT receive RIG—they simply receive more vaccine doses. 1

Common Pitfall to Avoid

• The most critical error is administering RIG to a previously vaccinated person, as this can suppress their protective anamnestic immune response. 1, 2

• Do not confuse "previously vaccinated" patients with "unvaccinated" patients—the protocols are completely different. 1, 4

• Never administer vaccine in the gluteal area, as this results in lower neutralizing antibody titers. 1, 4