Rabies Immunoglobulin Administration with 2nd or 3rd Vaccine Dose
Yes, rabies immunoglobulin (RIG) can be administered up to and including day 7 of the post-exposure prophylaxis series if it was not given on day 0, which means it can be given with the 2nd dose (day 3) or 3rd dose (day 7), but NOT beyond day 7. 1, 2
Optimal Timing and Window for RIG Administration
RIG should ideally be administered on day 0 (the same day as the first vaccine dose) to provide immediate passive immunity while the patient develops active antibody response to the vaccine. 1, 3
If RIG was not given on day 0, it can still be administered through day 7 of the post-exposure prophylaxis series, meaning it can accompany:
Beyond day 7, RIG is NOT indicated because an antibody response to the cell culture vaccine is presumed to have occurred by that time. 1, 2, 3
Critical Administration Requirements
RIG must NEVER be administered in the same syringe or at the same anatomical site as the first vaccine dose to avoid local interference with vaccine immunogenicity. 1, 4, 3
However, subsequent vaccine doses (days 3,7, and 14) CAN be administered in the same anatomical location where RIG was previously given, as the concern about interference only applies to simultaneous administration at the same site. 1
The full dose of RIG (20 IU/kg body weight) should be thoroughly infiltrated around and into the wound(s) if anatomically feasible, with any remaining volume injected intramuscularly at a site distant from vaccine administration. 1, 2, 3
Important Clinical Caveats
Do not exceed the recommended RIG dose (20 IU/kg), as excessive amounts can partially suppress active antibody production by the vaccine. 2, 4, 3
Previously vaccinated persons should NOT receive RIG at all, only the 2-dose vaccine booster (days 0 and 3), to avoid inhibiting the anamnestic immune response. 1, 5
Research evidence confirms that delayed RIG administration (up to 5 days after vaccine initiation) does not cause significant antibody suppression within the first month, supporting the guideline's day 7 cutoff. 6
Common Pitfall to Avoid
The most critical error is failing to give RIG entirely when indicated for previously unvaccinated persons with severe exposures, as the combination of vaccine plus RIG is nearly 100% effective when administered properly. 4, 3 If RIG is unavailable on day 0, do not skip it—administer it as soon as it becomes available, up through day 7. 2, 3