Should post solid organ transplant patients obtain repeat Measles, Mumps, and Rubella (MMR) titers?

From the Guidelines

Post-solid organ transplant patients should obtain repeat MMR (Measles, Mumps, Rubella) titers, but the decision to revaccinate should be made cautiously due to the live-attenuated nature of the vaccine and the patient's immunosuppressed state. These patients are at higher risk of infection due to immunosuppression, and their immunity to these diseases may wane over time, as noted in a study from 1. The study from 1 suggests that after allogeneic transplantation, the probability of becoming seronegative is significant for measles, mumps, and rubella, which mandates either revaccination or antibody testing against these viruses. However, as the MMR vaccine contains live attenuated viruses, it's generally contraindicated in immunosuppressed patients, as stated in 1. Therefore, revaccination should only be considered when the patient's immune function has sufficiently recovered and immunosuppression is at the lowest possible level, typically more than 24 months after transplantation, as recommended in 1. The rationale for checking titers is to maintain adequate immunity and prevent potentially severe infections that could compromise graft function or overall health. It's essential to note that the timing of vaccination or revaccination should be carefully coordinated with the patient's immunosuppression regimen and overall health status, and this decision should always be made in consultation with the transplant team to ensure the best balance between protective immunity and the risk of vaccine-related complications. Some key points to consider include:

• The patient's immune function and level of immunosuppression
• The risk of vaccine-related complications
• The potential benefits of revaccination in preventing severe infections
• The need for careful coordination with the transplant team to make informed decisions about vaccination and revaccination. In general, the approach to vaccination in post-solid organ transplant patients should prioritize their safety and the potential risks and benefits of vaccination, as outlined in 1 and 1.

From the Research

Post Solid Organ Transplant Patients and MMR Titers

• The decision to obtain repeat Measles, Mumps, and Rubella (MMR) titers in post solid organ transplant patients is complex and depends on various factors, including the patient's immune status and vaccination history 2, 3, 4, 5, 6.
• Studies have shown that immunocompromised patients, including solid organ transplant recipients, are at a higher risk of losing immunity to MMR due to immunosuppressive therapy 5, 6.
• The probability of being seropositive to MMR after solid organ transplantation is estimated to be around 60% for measles, 40% for mumps, and 50% for rubella 5.
• History of chronic graft-versus-host disease and low IgG index before transplantation are risk factors for the loss of immunity against MMR 5.
• Vaccination against MMR in post-transplant patients has been shown to be effective in restoring protective immunity, with seroconversion rates ranging from 64% to 97% for measles, 36% to 56% for mumps, and 72% to 97% for rubella 3, 5.
• However, the optimal number of doses and the role of measuring post-vaccination titers remain unknown 3.
• The American Society of Transplantation and other organizations recommend vaccination against MMR in solid organ transplant recipients without active chronic graft-versus-host disease or ongoing immunosuppressive therapy at 24 months after transplantation 2, 4.

Considerations for MMR Vaccination

• The safety and efficacy of live-attenuated MMR vaccines in post-transplant patients have been demonstrated in several studies, with no serious adverse reactions reported 2, 3.
• However, the risk of transmission and infection with live vaccines after liver transplantation has been reported, albeit rarely 2.
• Individual risk assessment is necessary to determine the suitability of MMR vaccination in post-transplant patients 2, 4.
• Standardized and simple criteria for the selection of suitable patients and the administration of the MMR vaccine are needed to ensure safe use 2.