MMR Vaccine for Treatment of Plantar Warts
Intralesional MMR vaccine is an effective treatment option for plantar warts with complete clearance rates of 65-87%, though it is not FDA-approved for this indication and should be considered only for resistant cases.
Mechanism and Efficacy
The MMR vaccine appears to work as an immunotherapeutic agent when injected directly into warts. Several studies have demonstrated its efficacy:
- Complete clearance rates of 87% have been reported in patients with recalcitrant plantar warts 1
- Another study showed 70% complete response rate with MMR compared to 45% with cryotherapy 2
- A randomized controlled trial demonstrated 65.2% complete clearance in resistant palmoplantar warts versus 23.85% in placebo group 3
However, one comparative study found MMR to be less effective (26.7%) than Candida albicans antigen (80%) for plantar warts 4.
Administration Protocol
When used for plantar warts, MMR vaccine is typically administered as follows:
- Intralesional injection into the base of the wart
- Repeated at 2-3 week intervals
- Continue until complete clearance or for a maximum of 3-5 treatments
- Follow-up for 2-9 months to detect recurrence
Safety Profile
The safety profile when used for warts includes:
- Pain during injection (reported in up to 82.6% of patients) 1
- Flu-like symptoms (reported in 4.3% of patients) 1
- No significant erythema, edema, or scarring reported
- Low recurrence rates (4.3% in one study) 1
Important Considerations and Contraindications
While the MMR vaccine is not FDA-approved for wart treatment, it's important to note standard MMR vaccine contraindications when considering this off-label use:
- Pregnancy: MMR vaccine should not be given to pregnant women due to theoretical risk of fetal harm 5
- Immunocompromised patients: MMR vaccine is contraindicated in severely immunocompromised individuals 5
- History of anaphylactic reactions: Those with history of anaphylaxis to eggs or neomycin should receive MMR vaccine only with extreme caution 5
- Recent immune globulin administration: MMR should be given at least 2 weeks before or 3-6 months after administration of immune globulin 5
Alternative Treatments
For context, other treatment options for plantar warts include:
- Cryotherapy (45% complete response rate) 2
- Intralesional Candida albicans antigen (80% complete response rate) 4
- Intralesional Hepatitis-B vaccine (43.8% complete response rate) 6
- Intralesional acyclovir (37.5% complete response rate) 6
Conclusion
While the MMR vaccine shows promise as an intralesional treatment for plantar warts, particularly resistant ones, it's important to note that this is an off-label use. The vaccine's primary purpose remains prevention of measles, mumps, and rubella 5, 7. The decision to use MMR for wart treatment should consider the patient's immune status, pregnancy status, and history of allergic reactions.