MMR Vaccination After IVIG for Kawasaki Disease
Children who have received high-dose IVIG (2 g/kg) for Kawasaki disease should defer MMR vaccination for 11 months after IVIG administration to ensure adequate vaccine response. 1
Rationale for the 11-Month Delay
The American Heart Association explicitly recommends deferring measles, mumps, rubella, and varicella immunizations for 11 months after high-dose IVIG administration because passively acquired antibodies from IVIG interfere with vaccine efficacy. 1 This interference occurs because the high concentration of measles-specific antibodies in IVIG can neutralize the live attenuated vaccine virus before the patient's immune system can mount an adequate response. 2
Evidence Supporting the 11-Month Interval
For standard 2 g/kg IVIG dosing: The 11-month interval is the established guideline recommendation in the United States for children receiving the standard 2 g/kg IVIG dose for Kawasaki disease. 1, 3
For IVIG-resistant disease requiring additional doses: When children receive additional IVIG (total 4 g/kg), measles antibody titers remain elevated at 6 months but become negative by 9 months post-infusion, suggesting a 9-month minimum interval may be sufficient for higher cumulative doses. 4 However, the American Heart Association guideline maintains the 11-month recommendation regardless of total IVIG dose. 1
Real-world vaccine efficacy data: A Japanese study demonstrated that MMR vaccination at 6 months after IVIG resulted in poor seroconversion rates (88% for measles, only 6% for mumps, 78% for rubella, and 16% for varicella), requiring booster doses at 12 months to achieve adequate immunity. 5 This confirms that earlier vaccination is suboptimal.
Special Circumstances and Exceptions
High measles exposure risk: Children at high risk for measles exposure may receive an early MMR dose before the 11-month interval, but they must be re-immunized 11 months after IVIG if serologic testing shows inadequate antibody response. 1 This approach balances immediate protection needs with the likelihood of vaccine failure.
Post-exposure prophylaxis: If a child who recently received IVIG for Kawasaki disease is exposed to measles, immune globulin (IG) at 0.25 mL/kg (maximum 15 mL) should be administered within 6 days of exposure rather than relying on MMR vaccination, which would be ineffective due to circulating IVIG antibodies. 2
Practical Implementation Algorithm
Document IVIG date: Record the exact date of IVIG completion (not initiation) in the child's immunization record. 1
Calculate vaccination date: Schedule MMR for 11 months after the IVIG completion date. 1
Coordinate with routine schedule: If the 11-month delay pushes MMR beyond the routine 12-15 month schedule, administer it at 11 months post-IVIG regardless of the child's age. 1
Ensure second dose: The second MMR dose should still be given before school entry (age 4-6 years) as routinely recommended. 2
Common Pitfalls to Avoid
Calculating from disease onset rather than IVIG date: The 11-month interval begins from IVIG completion, not from Kawasaki disease diagnosis or fever onset. 1
Administering MMR at the routine 12-month visit: If a child received IVIG at age 6 months, the routine 12-month MMR would occur only 6 months post-IVIG and should be deferred. Real-world data show that 76% of children breach this guideline for their first MMR dose, representing a significant gap in practice. 6
Forgetting to update immunization registries: Immunization systems often auto-schedule MMR at 12 months without accounting for IVIG history, leading to inappropriate early vaccination. 6
Assuming shorter intervals for incomplete Kawasaki disease: Even children with incomplete Kawasaki disease who receive IVIG require the same 11-month deferral. 1, 3
Additional Safety Considerations for Children Post-Kawasaki Disease
While awaiting MMR vaccination, children on long-term aspirin therapy (those with coronary abnormalities) require annual influenza vaccination to reduce Reye syndrome risk during influenza infection. 1 Parents should be instructed to contact the physician immediately if the child develops symptoms of or is exposed to influenza or varicella while on aspirin therapy. 1