From the Guidelines
Post-transplant patients should obtain repeat MMR (Measles, Mumps, Rubella) titers at least 24 months after transplantation, as recommended by the CDC 1. This is because transplant recipients are at higher risk of complications from infections, including measles, mumps, and rubella, due to their immunocompromised state. The MMR vaccine is a live vaccine and is generally contraindicated in the immediate post-transplant period due to the risk of vaccine-strain infection in immunosuppressed patients. However, as time passes and immunosuppression is reduced, some patients may benefit from revaccination to ensure protection against these diseases. The decision to revaccinate should be made on a case-by-case basis, considering factors such as:
- The patient's current level of immunosuppression
- Time since transplantation
- Risk of exposure to these diseases
- Overall health status Checking titers helps identify patients who may have lost immunity post-transplant and guides decisions about revaccination. According to the European Myeloma Network, antibodies for various pathogens, including measles, are significantly reduced after autologous and allogeneic stem cell transplantation 1. The IDSA considers recipients of allotransplantation as never vaccinated, highlighting the need for a full vaccination program 1. Therefore, repeat MMR titers should be obtained at least 24 months after transplantation to guide decisions about revaccination and ensure protection against measles, mumps, and rubella.
From the Research
Post-Transplant MMR Titer Assessment
- The decision to obtain repeat Measles, Mumps, and Rubella (MMR) titers in post-transplant patients is crucial for ensuring their protection against these vaccine-preventable diseases 2, 3, 4, 5, 6.
- Studies have shown that post-transplant patients may lose immunity to MMR over time, making them susceptible to infection 4, 5, 6.
- The probability of being seropositive to measles, mumps, or rubella after allogeneic stem cell transplantation (allo-HCT) is estimated to be around 60.6% for measles, 39.7% for mumps, and 52.2% for rubella at 2 years after transplantation 6.
Vaccination Strategies
- MMR vaccination can be considered for post-transplant patients who are not protected against these diseases, following an individual risk assessment 2, 3, 4.
- The use of live viral vaccines, such as MMR, in transplant recipients on immunosuppression may be a reasonable strategy, with preliminary data suggesting efficacy and safety 3.
- One dose of MMR vaccine can elicit protective titers in the majority of patients, and a second vaccine dose can be immunogenic in non-responders 5.
Monitoring and Follow-Up
- Regular monitoring of MMR titers is essential to assess the need for vaccination or revaccination in post-transplant patients 5, 6.
- The measurement of post-vaccination titers can help determine the effectiveness of the vaccine and the need for additional doses 5.
- History of chronic graft-versus-host disease may be a risk factor for the loss of immunity against measles and rubella, highlighting the need for close monitoring in these patients 6.