Management and prevention of varicella and measles infections in pediatric solid organ transplant candidates and recipients: An IPTA survey of current practice

Live-attenuated vaccination for measles, mumps, and rubella in pediatric liver transplantation

BACKGROUND

Infections are a serious short- and long-term problem after pediatric organ transplantation. In immunocompromised patients, they can lead to transplant rejection or a severe course with a sometimes fatal outcome. Vaccination is an appropriate means of reducing morbidity and mortality caused by vaccine-preventable diseases. Unfortunately, due to the disease or its course, it is not always possible to establish adequate vaccine protection against live-attenuated viral vaccines (LAVVs) prior to transplantation. LAVVs such as measles, mumps, and rubella (MMR) are still contraindicated in solid organ transplant recipients receiving immunosuppressive therapy (IST), thus creating a dilemma.

AIM

This review discusses whether, when, and how live-attenuated MMR vaccines can be administered effectively and safely to pediatric liver transplant recipients based on the available data.

MATERIAL AND METHODS

We searched PubMed for literature on live-attenuated MMR vaccination in pediatric liver transplantation (LT).

RESULTS

Nine prospective observational studies and three retrospective case series were identified in which at least 833 doses of measles vaccine were administered to 716 liver transplant children receiving IST. In these selected patients, MMR vaccination was well tolerated and no serious adverse reactions to the vaccine were observed. In addition, an immune response to the vaccine was demonstrated in patients receiving IST.

CONCLUSION

Due to inadequate vaccine protection in this high-risk group, maximum efforts must be made to ensure full immunization. MMR vaccination could also be considered for unprotected patients after LT receiving IST following an individual risk assessment, as severe harm from live vaccines after liver transplantation has been reported only very rarely. To this end, it is important to establish standardized and simple criteria for the selection of suitable patients and the administration of the MMR vaccine to ensure safe use.

Spotting a potential threat: Measles among pediatric solid organ transplantation recipients

BACKGROUND

Low-vaccination rates worldwide have led to the re-emergence of vaccine-preventable infections, including measles. Immunocompromised patients, including pediatric solid organ transplant (SOT) recipients, are at risk for measles because of suboptimal vaccination, reduced or waning vaccine immunity, lifelong immunosuppression, and global re-emergence of measles.

OBJECTIVES

To review published cases of measles in pediatric SOT recipients to heighten awareness of its clinical manifestations, summarize diagnostic and treatment strategies, and identify opportunities to optimize prevention.

METHODS

We conducted a literature review of published natural measles infections in SOT recipients ≤21 years of age, summarizing management and outcomes. We describe measles epidemiology, recommended diagnostics, treatment, and highlight prevention strategies.

RESULTS

There are seven published reports of measles infection in 12 pediatric SOT recipients, the majority of whom were unvaccinated or incompletely vaccinated. Subjects had atypical or severe clinical presentations, including lack of rash and complications, most frequently with encephalitis and pneumonitis, resulting in 33% mortality. Updated recommendations on testing and vaccination are provided. Treatment options beyond supportive care and vitamin A are limited, with no approved antivirals.

CONCLUSION

While measles is infrequently reported in pediatric SOT recipients, morbidity and mortality remain significant. A high index of suspicion is warranted in susceptible SOT recipients with clinically compatible illness or exposure. Providers must recognize this risk, educate families, and be aware of both classic and atypical presentations of measles to rapidly identify, isolate, and diagnose measles in pediatric SOT recipients. Continued efforts to optimize measles vaccination both pre- and post-SOT are warranted.

Approaches to pretransplant vaccination

PURPOSE OF REVIEW

The aim of this study was to summarize new data and perspectives in pretransplant vaccination, with a particular focus on COVID-19 vaccination and vaccination requirements.

RECENT FINDINGS

Pretransplant vaccination produces superior markers of immunity and is expected to have greater clinical benefit, compared with posttransplant vaccination. As such, efforts are underway to identify and characterize barriers to pretransplant vaccination, with a particular focus on COVID-19 vaccine hesitancy. Unfortunately, vaccine hesitancy is common in transplant patients, often motivated by individual side effect and safety concerns. COVID-19 vaccination requirements have been implemented in some centres, informed by ethical principles, including beneficence, utility and justice.

SUMMARY

Barriers to pretransplant vaccination can be understood in three categories: hard stops, including issues of vaccine availability, eligibility, safety and feasibility; soft stops, including issues of convenience, prioritization and care coordination; and volitional stops related to vaccine hesitancy and refusal. All of these barriers present opportunities for improvement based on recent data.

Quality improvement project to improve vaccinations in the pediatric liver transplant population

OBJECTIVES

A quality improvement approach was used to increase pediatric liver transplant recipient live and inactive vaccination rates by assessing titers and recommending vaccinations.

METHODS

A new screening and immunization process for both live and inactive vaccines was discussed with families at their annual visit. Antibody titers for varicella, measles, mumps, rubella, Haemophilus influenzae type B, hepatitis A, and hepatitis B were obtained. Specific criteria were developed for live virus vaccination candidacy. Vaccines were recommended based on patient titers and vaccination candidacy criteria. Surveillance for adverse effects to live vaccines was performed. Repeat titers were obtained approximately 1-month post-vaccine administration.

RESULTS

After PDSA cycle 1, 99% (71/72) of pediatric liver transplant patients had titers obtained. Live vaccines were recommended for 32 patients and 16 (50%) were vaccinated. Inactive vaccines were recommended to 64 patients, and 31 (48%) were vaccinated. Eight of 13 (62%) patients with follow-up titers achieved immunity for inactive vaccines. Zero patients had an adverse reaction to any live vaccine. Ten of 12 (83%) patients with follow-up titers achieved immunity from live vaccines. The most common barriers to receive live vaccines included not scheduling appointment with primary care provider (n = 3) and "non-vaccinators" (n = 3).

CONCLUSIONS

Administering live and inactive vaccines to select pediatric liver transplant patients appears to be safe and effective in our studied population. For PDSA cycle 2, we will continue our current practice and consider offering vaccines in transplant clinic, since this was a barrier to vaccination identified during PDSA cycle 1.

Live Vaccines in Pediatric Liver Transplant Recipients: "To Give or Not to Give"

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