What if a patient's previous rabies vaccine (Human Diploid Cell Vaccine (HDCV), Purified Chick Embryo Cell Vaccine (PCECV), or Rabies Vaccine, Adsorbed (RVA)) dose schedule is not completed?

Management of Incomplete Rabies Vaccine Series

If a patient has not completed their previous rabies vaccine schedule, continue the series from where it stopped without restarting—delays of even several months do not require reinitiation of the entire series. 1

Core Principle: Resume, Don't Restart

• The CDC and ACIP guidelines clearly state that most interruptions in the vaccine schedule do not require reinitiation of the entire series, regardless of the time elapsed 1
• Administer the remaining doses as soon as possible, maintaining the same intervals as the original schedule 1
• Delays of a few days for individual doses are clinically unimportant, and even longer lapses of weeks to months do not necessitate restarting 1, 2

Practical Application by Scenario

For Previously Unvaccinated Persons Who Started PEP

• If 1-3 doses were given: Resume immediately with the next dose in sequence, then continue with remaining doses at standard intervals (days 3,7, and 14 from the original day 0) 1
• Example: A patient who received only 2 doses and had a 5-month lapse should receive the third dose immediately, then the fourth dose 7 days later 1
• The standard 4-dose regimen (days 0,3,7,14) remains the target schedule for immunocompetent individuals 3

For Immunocompromised Patients

• These patients require special consideration and should receive the full 5-dose regimen (days 0,3,7,14,28) even if previously started on a 4-dose schedule 3
• If the series was interrupted, restart the entire 5-dose series rather than continuing from where stopped 1
• Mandatory serologic testing 7-14 days after the final dose is required to confirm adequate antibody response (≥1:5 dilution by RFFIT) 3, 1

For Previously Vaccinated Persons

• If a previously vaccinated person (completed prior ACIP-recommended regimen with cell-culture vaccines) has an incomplete current PEP series, they only need 2 total doses on days 0 and 3 3
• Do NOT administer HRIG to previously vaccinated persons, as it inhibits the anamnestic response 3

HRIG Administration Window

• If HRIG was not given initially, it can still be administered up to and including day 7 of the vaccine series 3
• After day 7, HRIG should NOT be given as it may suppress active antibody production 1, 2
• This applies only to previously unvaccinated persons; previously vaccinated individuals should never receive HRIG 3

Serologic Testing Considerations

• Routine antibody testing is NOT necessary for healthy immunocompetent patients completing at least 4 doses 3
• For patients with substantial schedule deviations or prolonged interruptions, consider serologic testing 7-14 days after the final dose to confirm adequate response 1, 2
• Serum should completely neutralize challenge virus at ≥1:5 dilution by RFFIT 3, 1
• Testing is mandatory for immunosuppressed patients regardless of schedule adherence 1

Supporting Evidence for Continuation Approach

• The CDC estimates that over 1,000 persons annually in the U.S. receive only 3-4 doses with no documented rabies cases, even when exposed to confirmed rabid animals 1
• No case of human rabies in the United States has been attributed to receiving less than the 5-dose vaccine course, supporting continuation rather than restarting 1
• This evidence demonstrates that immunologic memory persists even with incomplete series 1

Critical Pitfalls to Avoid

• Do NOT restart the entire series for schedule interruptions in immunocompetent patients—this wastes vaccine and delays completion 1
• Do NOT withhold treatment based on time elapsed since exposure—PEP should begin immediately upon recognition of exposure, even if months have passed 2
• Do NOT administer vaccine in the gluteal area—this produces inadequate antibody response and has been associated with vaccine failure 3, 2
• Do NOT give HRIG to previously vaccinated persons or after day 7 of the vaccine series 3, 1, 2