What are the guidelines for a missed dose of anti-rabies (rabies) vaccination?

Missed Dose of Anti-Rabies Vaccination: Management Guidelines

Primary Recommendation

When a patient misses a scheduled dose of rabies post-exposure prophylaxis, administer the missed dose immediately upon presentation and resume the vaccination schedule from that point, maintaining the same intervals between remaining doses—do not restart the entire series. 1

Key Management Principles

For Minor Schedule Deviations

• Delays of a few days for individual doses are considered unimportant and do not compromise protection. 1
• Simply give the missed dose when the patient presents and continue with the remaining doses at the appropriate intervals from that point. 1
• Most interruptions in the vaccine schedule do not require restarting the entire series. 1

Standard Vaccination Schedule Context

The current CDC-recommended schedule for previously unvaccinated persons consists of:

• 4 doses administered intramuscularly on days 0,3,7, and 14 (day 0 is when the first dose is given). 2, 1, 3
• Human rabies immune globulin (HRIG) at 20 IU/kg administered once on day 0. 2, 3

Specific Catch-Up Scenarios

Previously Unvaccinated Persons (4-Dose Series)

• If a dose is missed at any point in the series, administer it as soon as the patient returns and adjust subsequent doses accordingly. 1
• For example, if the day 7 dose is missed and the patient presents on day 10, give that dose immediately and schedule the final dose 4 days later (maintaining the ~7-day interval). 1

Previously Vaccinated Persons (2-Dose Series)

• Only 2 doses are required (days 0 and 3), so if one is missed, administer it as soon as possible. 1
• No HRIG is needed for previously vaccinated individuals. 2, 3

Immunocompromised Patients (5-Dose Series)

• These patients require the 5-dose schedule (days 0,3,7,14, and 28) with HRIG. 1, 3
• Apply the same catch-up principle: give the missed dose immediately and continue the series. 1

Critical Timing Considerations for HRIG

HRIG Administration Window

• If HRIG was not given on day 0, it can still be administered up to and including day 7 of the post-exposure prophylaxis series. 2, 1, 3
• Beyond day 7, HRIG is not indicated as antibody response to the vaccine is presumed to have occurred. 1
• HRIG should never be given to previously vaccinated persons as it will inhibit the anamnestic response. 2, 3

When to Consider Serologic Testing

For Substantial Deviations

• If there are substantial deviations from the recommended schedule (lapses of weeks or more), assess immune status by performing serologic testing 7-14 days after administration of the final dose. 1
• The effect of longer lapses is unknown, making serologic confirmation prudent in these cases. 1
• Serum should completely neutralize challenge virus at least at a 1:5 dilution by RFFIT. 2

Routine Testing Not Required

• No routine serologic testing is necessary for healthy patients completing post-exposure prophylaxis on schedule. 2

Critical Pitfalls to Avoid

Do Not Restart the Series

• The most common error is unnecessarily restarting the entire vaccination series when a dose is missed—this wastes vaccine and delays completion of prophylaxis. 1

Maintain Proper Injection Sites

• Always use the deltoid muscle for adults and older children, or anterolateral thigh for young children. 2, 1, 3
• Never use the gluteal area as this produces inadequate antibody response and has been associated with vaccine failure. 2, 3, 4

HRIG Timing and Dosing

• Do not exceed the recommended HRIG dose of 20 IU/kg as this can suppress active antibody production. 3, 4
• HRIG should not be administered in the same syringe or anatomic site as the vaccine. 2, 3

Urgency of Completing Prophylaxis

Every attempt should be made to complete the vaccination series because rabies is nearly 100% fatal once clinical symptoms develop. 1, 3 Even if recognition of exposure is delayed by weeks or months, post-exposure prophylaxis should still be initiated as there is no absolute cutoff beyond which treatment should be withheld. 3