Acute measles infection triggering an episode of liver transplant rejection

Diminished measles immunity after paediatric liver transplantation-A retrospective, single-centre, cross-sectional analysis

Liver transplantation in childhood has an excellent long-term outcome, but is associated with a long-term risk of infection. Measles is a vaccine-preventable infection, with case series describing severe courses with graft rejection, mechanical ventilation and even death in liver transplant recipients. Since about 30% of liver transplanted children receive liver transplants in their first year of life, not all have reached the recommended age for live vaccinations. On the contrary, live vaccines are contraindicated after transplantation. In addition, vaccination response is poorer in individuals with liver disease compared to healthy children. This retrospective, single-centre, cross-sectional study examines measles immunity in paediatric liver transplant recipients before and after transplantation. Vaccination records of 239 patients, followed up at Hannover Medical School between January 2021 and December 2022 were analysed. Twenty eight children were excluded due to stem cell transplantation, regular immunoglobulin substitution or measles vaccination after transplantation. More than 55% of all 211 children analysed and 75% of all those vaccinated at least once are measles seropositive after transplantation-48% after one and 84% after two vaccinations-which is less than in healthy individuals. Interestingly, 26% of unvaccinated children also showed measles antibodies and about 5-15% of vaccinated patients who were seronegative at the time of transplantation were seropositive afterwards, both possibly through infection. In multivariable Cox proportional hazards regression, the number of vaccinations (HR 4.30 [95% CI 2.09-8.83], p<0.001), seropositivity before transplantation (HR 2.38 [95% CI 1.07-5.30], p = 0.034) and higher age at time of first vaccination (HR 11.5 [95% CI 6.92-19.1], p<0.001) are independently associated with measles immunity after transplantation. In contrast, older age at testing is inversely associated (HR 0.09 [95% CI 0.06-0.15], p<0.001), indicating a loss of immunity. Vaccination in the first year of life does not pose a risk of non-immunity. The underlying liver disease influences the level of measles titres of twice-vaccinated patients; those with acute liver failure being the lowest compared to children with metabolic disease. In summary, vaccine response is poorer in children with liver disease. Liver transplant candidates should be vaccinated before transplantation even if this is earlier in the first year of life. Checking measles IgG and re-vaccinating seronegative patients may help to achieve immunity after transplantation.

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.

Seroprevalence of Measles, Mumps, Rubella, and Varicella-Zoster Virus and Seroresponse to the Vaccinations in Adult Solid Organ Transplant Candidates

BACKGROUND

Updating live vaccines such as measles, mumps, rubella, and varicella (MMRV) is an important step in preparing patients for solid organ transplant (SOT) to prevent morbidity from these preventable diseases. However, data for this approach are scarce. Thus, we aimed to describe the seroprevalence of MMRV and the efficacy of the vaccines in our transplant center.

METHODS

Pre-SOT candidates >18 y of age were retrospectively retrieved from SOT database in Memorial Hermann Hospital Texas Medical Center. MMRV serologies are routinely screened at the time of pretransplant evaluation. We divided patients into 2 groups: MMRV-positive group versus MMRV-negative group, patients with positive all MMRV serologies and with negative immunity to at least 1 dose of MMRV, respectively.

RESULTS

A total of 1213 patients were identified. Three hundred ninety-four patients (32.4%) did not have immunity to at least 1 dose of MMRV. Multivariate analysis was conducted. Older age (odds ratio [OR]: 1.04) and liver transplant candidates (OR: 1.71) were associated with seropositivity. Previous history of SOT (OR: 0.54) and pancreas/kidney transplant candidates (OR: 0.24) were associated with seronegativity. Among 394 MMRV seronegative patients, 60 patients received 1 dose of MMR vaccine and 14 patients received 1 dose of varicella-zoster virus vaccine without severe adverse events. A total of 35% (13/37) of patients who had follow-up serologies did not have a serological response.

CONCLUSIONS

A significant number of pre-SOT candidates were not immune to at least 1 dose of MMRV. This highlights the importance of MMRV screening and vaccinations pre-SOT. Postvaccination serological confirmation should be performed to evaluate the necessity for a second dose.

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.

The limits of refusal: An ethical review of solid organ transplantation and vaccine hesitancy

Patients pursuing solid organ transplantation are encouraged to receive many vaccines on an accelerated timeline. Vaccination prior to transplantation offers the best chance of developing immunity and may expand the pool of donor organs that candidates can accept without needing posttransplant therapy. Furthermore, transplant recipients are at greater risk for acquiring vaccine-preventable illnesses or succumbing to severe sequelae of such illnesses. However, a rising rate of vaccine refusal has challenged transplant centers to address the phenomenon of vaccine hesitancy. Transplant centers may need to consider adopting a policy of denial of solid organ transplantation on the basis of vaccine refusal for non-medical reasons (i.e., philosophical or religious objections or personal beliefs that vaccines are unnecessary or unsafe). Arguments supporting such a policy are motivated by utility, stewardship, and beneficence. Arguments opposing such a policy emphasize justice and respect for persons, and seek to avoid worsening inequities or medical coercion. This paper examines these arguments and situates them within the special cases of pediatric transplantation, emergent transplantation, and living donation. Ultimately, a uniform national policy addressing vaccine refusal among transplant candidates is needed to resolve this ethical dilemma and establish a consistent, fair, and standard approach to vaccine refusal in transplantation.

Live vaccines after pediatric solid organ transplant: Proceedings of a consensus meeting, 2018

Growing evidence suggests receipt of live-attenuated viral vaccines after solid organ transplant (SOT) has occurred and is safe and needed due to lapses in herd immunity. A 2-day consortium of experts in infectious diseases, transplantation, vaccinology, and immunology was held with the objective to review evidence and create expert recommendations for clinicians when considering live viral vaccines post-SOT. For consideration of VV and MMR post-transplant, evidence exists only for kidney and liver transplant recipients. For MMR vaccine post-SOT, consider vaccination during outbreak or travel to endemic risk areas. Patients who have received antiproliferative agents (eg. mycophenolate mofetil), T cell-depleting agents, or rituximab; or have persistently elevated EBV viral loads, or are in a state of functional tolerance, should be vaccinated with caution and have a more in-depth evaluation to define benefit of vaccination and net state of immune suppression prior to considering vaccination. MMR and/or VV (not combined MMRV) is considered to be safe in patients who are clinically well, are greater than 1 year after liver or kidney transplant and 2 months after acute rejection episode, can be closely monitored, and meet specific criteria of "low-level" immune suppression as defined in the document.

Vaccinations in pediatric kidney transplant recipients

Pediatric kidney transplant (KT) candidates should be fully immunized according to routine childhood schedules using age-appropriate guidelines. Unfortunately, vaccination rates in KT candidates remain suboptimal. With the exception of influenza vaccine, vaccination after transplantation should be delayed 3-6 months to maximize immunogenicity. While most vaccinations in the KT recipient are administered by primary care physicians, there are specific schedule alterations in the cases of influenza, hepatitis B, pneumococcal, and meningococcal vaccinations; consequently, these vaccines are usually administered by transplant physicians. This article will focus on those deviations from the normal vaccine schedule important in the care of pediatric KT recipients. The article will also review human papillomavirus vaccine due to its special importance in cancer prevention. Live vaccines are generally contraindicated in KT recipients. However, we present a brief review of live vaccines in organ transplant recipients, as there is evidence that certain live virus vaccines may be safe and effective in select groups. Lastly, we review vaccination of pediatric KT recipients prior to international travel.

Rare and Emerging Viral Infections in the Transplant Population

Viral infections account for a large proportion of emerging infectious diseases, and the agents included in this group consist of recently identified viruses as well as previously identified viruses with an apparent increase in disease incidence. In transplant recipients, this group can include viruses with no recognized pathogenicity in immunocompetent patients and those that result in atypical or more severe disease presentations in the immunocompromised host. In this chapter, we begin by discussing viral diagnostics and techniques used for viral discovery, specifically as they apply to emerging and rare infections in this patient population. Focus then shifts to specific emerging and re-emerging viruses in the transplant population, including human T-cell leukemia virus 1, rabies, lymphocytic choriomeningitis virus, human bocavirus, parvovirus 4, measles, mumps, orf, and dengue. We have also included a brief discussion on emerging viruses and virus families with few or no reported cases in transplant recipients: monkeypox, nipah and hendra, chikungunya and other alphaviruses, hantavirus and the Bunyaviridae, and filoviruses. Finally, concerns regarding infectious disease complications in xenotransplantation and the reporting of rare viral infections are addressed. With the marked increase in the number of solid organ and hematopoietic stem cell transplants performed worldwide, we expect a corresponding rise in the reports of emerging viral infections in transplant hosts, both from known viruses and those yet to be identified.

Measles hepatitis in a vaccinated liver transplant recipient: case report and review of literature

Measles infection, postliver transplant, may lead to a fatal graft loss. Individuals who have been previously exposed to the measles antigen may have a modified disease presentation. Although vaccination may not provide solid immunity, it ameliorates the severity of the disease.

Vaccinations, response, and controls before and after intestinal transplantation in children

Vaccination is an effective strategy to decrease infections in transplant recipients. Children after intestinal transplantation carry a high risk of infection due to increased immunosuppression. In a series of 22 children after intestinal transplantation, we studied the vaccination schedules and the antibodies against vaccine-preventable diseases before transplantation, and at one and five yr after transplantation. We reviewed whether the vaccination schedules were complete, and we analysed the factors that may influence serological immunity and the incidence of disease in patients with deficient immunity. All patients completed the recommended vaccination schedules for DTaP-IPV and HBV. After transplantation, the negative antibodies against vaccine-preventable diseases were mostly related to an antirejection therapy: for DTaP-IPV: four of four patients with no antibody had been treated for rejection, for HBV: two of five, HAV: three of four, MMR: three of seven, and VZV: three of four. A post-transplantation varicella infection was followed by acute rejection, with probability for a relationship between both events. We observed 50% of varicella cases in unvaccinated children, highlighting the importance of pretransplant vaccination. Waning immunogenicity mediated by antibodies against vaccine-preventable disease after transplantation indicated a need for boosters. The recommendations should be regularly enforced, as the reliance on routine immunizations schedules is not adequate in immunocompromised patients.

Live virus vaccines in transplantation: friend or foe?

Solid organ and hematopoietic stem cell transplant recipients may be exposed to diseases which may be prevented through live attenuated virus vaccines (LAVV). Because of their immunosuppression, these diseases can lead to severe complications in transplant recipients. Despite increasing evidence regarding the safety and effectiveness of certain LAVV, these vaccines are still contraindicated for immunocompromised patients, such as transplant recipients. We review the available studies on LAVV, such as varicella zoster, measles-mumps-rubella, influenza, yellow fever, polio, and Japanese encephalitis vaccines in transplant patients. We discuss the current recommendations and the potential risks, as well as the expected benefits of LAVV immunization in this population.

Other viral infections in solid organ transplantation

Viral infections are a major cause of morbidity and even mortality in solid organ transplant recipients. This article reviews key aspects of infections in solid organ transplant recipients from respiratory viruses, such as influenza, polyomavirus, erythrovirus B19 and measles.

An update on immunizations before and after transplantation in the pediatric solid organ transplant recipient

Vaccination offers a unique opportunity to decrease the burden of infectious complications following solid organ transplantation. In this paper we review the current guidelines for routine immunizations before and after solid organ transplantation, including the recent updates and changes to recommendations for certain vaccines. We also address the issue of waning immunity in solid organ transplant recipients and discuss the current data on vaccinating this patient population with live vaccines after transplantation.