Immunization practices among pediatric transplant hepatologists

Detection of viral RNA and DNA and immune response following administration of live attenuated measles and varicella vaccines in children with chronic liver disease

Infections preventable by live virus vaccines are surging in the setting of decreased herd immunity. Many children with chronic liver diseases (CLDs) are unimmunized and at increased risk for infection due to guidelines recommending against live vaccines within 4 weeks pretransplant. This prospective study of 21 children with CLD and 13 healthy controls defined the timing of measles virus and varicella-zoster virus (VZV) RNA- and DNA-emia following vaccination and compared immune responses to measles and varicella vaccines in both groups. Measles virus RNA and VZV DNA real-time PCR were measured weekly following vaccination; measles virus RNA was undetectable in all by 14 days postvaccination, but VZV DNA, which can be managed with antivirals, was detected in 1 child in the CLD group at 21 days and 1 control at 28 days postvaccination. Humoral or cell-mediated vaccine response was 100% to measles virus and 94% to VZV in the CLD group postvaccination, whereas it was 100% to both vaccines in controls. Our pilot study suggests that both live vaccines can be safely and effectively administered up to 14 days prior to transplantation in children with CLD. We anticipate this will improve vaccination rates and thus decrease rates of vaccine-preventable infections in vulnerable children with CLD.

Live-Attenuated Vaccines in Pediatric Solid Organ Transplant

Measles, mumps, rubella (MMR), and varicella incidence rates have increased due to the delayed vaccination schedules of children secondary to the COVID-19 pandemic. Decreased herd immunity creates a risk for immunocompetent children and immunocompromised individuals in the community. Historically, live-attenuated vaccines (MMR and varicella) were recommended before solid organ transplants. The amount of time before transplant when this is appropriate is often debated, as is the utility of vaccine titers. MMR and varicella vaccines previously were not recommended in immunocompromised patients post-solid organ transplant due to the undue risk of transmission and posed infection risk. The new literature on live-attenuated vaccines in post-transplant pediatric patients provides more insight into the vaccines' safety and efficacy. The present article aims to provide guidance on live-attenuated vaccines (MMR and varicella) in the pre-transplant and post-operative solid organ transplant phases of care in pediatric patients.

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.

Adherence to recommended vaccination policies for pre- and post-solid organ transplantation patients: A national questionnaire survey in Japan

BACKGROUND

Pre-transplant vaccination is recommended for patients undergoing solid organ transplantation (SOT). While appropriate vaccination protocols are implemented at some facilities, transplantation is sometimes performed with inadequate preoperative vaccine management. Vaccination rates vary across facilities, but those of SOT centers in Japan have never been investigated. This study aimed to conduct a nationwide questionnaire survey to assess pre- and post-transplant vaccination policies among SOT facilities in Japan.

METHODS

The survey was conducted from September to November 2022. All registered (n = 221) solid organ (namely, the lungs, liver, kidneys, pancreas, heart, and small intestine) transplant facilities were asked to complete a web-based survey.

RESULTS

The survey response rate was 70.2 %. Live and inactivated vaccines were recommended at 64.9 % and 68.9 % of the responding facilities, respectively. The following vaccines were incorporated into the vaccination protocols of facilities: pneumococcal vaccine, 31.7 % (13-valent pneumococcal conjugate vaccine) and 65.4 % (23-valent pneumococcal polysaccharide vaccine); hepatitis B virus vaccine, 67.3 %; severe acute respiratory syndrome coronavirus 2 vaccine, 73.1 %; influenza vaccine, 73.1 %; and zoster vaccines, 23.1 %. The reasons for unresponsiveness to vaccinations included inadequate time before transplantation (60.3 %), cost burden (41.1 %), high number of vaccinations (21.9 %), no recognition of the need for vaccination (17.9 %), and the requirement to explain the need for vaccination (15.2 %).

CONCLUSIONS

Our study revealed gaps in vaccination practices across nationwide facilities in Japan. The findings indicate the importance of promoting scheduled efficiency and encouraging the national health system to reduce vaccine costs with the support of public subsidies.

Immunization of Solid Organ Transplant Candidates and Recipients: A 2022 Update

Immunizations are a relatively safe and cost-effective intervention to prevent morbidity and mortality associated with vaccine preventable infection (VPIs). As such, immunizations are a critical part of the care of pre and posttransplant patients and should be prioritized. New tools are needed to continue to disseminate and implement the most up-to-date vaccine recommendations for the SOT population. These tools will help both primary care providers and multi-disciplinary transplant team members taking care of transplant patients to stay abreast of evidence-based best practices regarding the immunization of the SOT patient.

Hepatitis A Immunity and Paediatric Liver Transplantation-A Single-Centre Analysis

Following paediatric solid organ liver transplantation, risk of infection is high, both in the short and long term. Even though an infection with hepatitis A virus (HAV) is often asymptomatic and self-limited in children, some case studies describe severe cases leading to death. Vaccinations offer simple, safe and cheap protection. However, data on vaccination rates against hepatitis A in children with liver disease are scarce. Moreover, the vaccine is only approved from the age of one year old. At the same time, up to 30% of children with liver disease are transplanted within the first year of life, so the window of opportunity for vaccination is limited. This retrospective, observational, single-centre study examines the HAV immunity in paediatric liver transplant recipients before and after the first year of transplantation. Vaccination records of 229 of 279 (82.1%) children transplanted between January 2003 and June 2021 were analysed. Of 139 eligible children aged ≥ 1 year old, only 58 (41.7%) were vaccinated at least with one HAV dose prior to transplantation. In addition, seven patients received the vaccine below one year of age. After one or two doses, 38.5% or 90.6% of 65 patients were anti-HAV-IgG positive, respectively. This percentage remained stable up to the first annual check-up. For children vaccinated only once, a shorter interval from vaccination to transplantation is a risk factor for lack of immunity. Thus, HAV immunisation should be started earlier in liver transplant candidates to improve immunity in this high-risk group.

Low post-transplant measles and varicella titers among pediatric liver transplant recipients: A 10-year single-center study

BACKGROUND

Vaccine preventable illnesses are important sources of morbidity, mortality, and increased healthcare costs in pediatric LT recipients. Our aim was to measure the seroprevalence of antibodies to measles and VZV in this population.

METHODS

We conducted a retrospective chart review of 44 patients who received LT before age 18 at UCLA Mattel Children's Hospital from January 2008 to December 2017.

RESULTS

Median age at transplantation was 2.5 years (IQR 1.2-7.7). Post-transplant measles antibodies were present in 17 of 37 patients (46%); risk factors for seronegativity included younger age at transplant (p = .02) and greater time from transplant to testing (p = .04). Post-transplant VZV antibodies were present in 17 of 39 patients (44%); risk factors for seronegativity included greater time from transplant to testing (p = .04). 6 of 16 patients (38%) who tested positive for pre-transplant VZV antibodies tested negative after transplantation. Fourteen of 20 patients (70%) with at least 1 documented dose of the MMR vaccine tested positive for post-transplant measles antibodies. Ten of 20 of patients (50%) with at least 1 documented dose of the VZV vaccine tested positive for post-transplant VZV antibodies. We also describe 10 patients who received post-transplant measles and VZV vaccines without documented complications.

CONCLUSIONS

Our study suggests that pediatric LT patients are at greater risk of contracting measles and VZV despite vaccination status, and that prevalence of measles and VZV antibodies decreases as time from transplantation increases. This should weigh into the institutional risk-benefit assessment when deciding whether or not to administer LAVs to these patients.

Vaccination in Chronic Liver Disease: An Update

Patients with chronic liver disease (CLD) with or without cirrhosis remain at risk of developing hepatic decompensation when infected with viral or bacterial pathogens. The Advisory Committee on Immunization Practices (ACIP) currently recommends vaccination in CLD against hepatitis A virus (HAV), hepatitis B virus (HBV), influenza, pneumococcus, herpes zoster, tetanus, diphtheria, pertussis, and SARS-CoV-2. Inactivated vaccines are preferred over live attenuated ones, especially in transplant recipients where live vaccines are contraindicated. As the severity of the liver disease progresses, vaccine efficacy declines, and therefore, vaccines should be ideally administered early in the disease course for optimal immune response. Despite the strong recommendations, overall vaccination coverage in CLD remains poor; however, it is encouraging to note that in recent years coverage against influenza and pneumococcus has shown some improvement. Inadequate access to healthcare, lack of information on vaccine safety, poor financial reimbursement for healthcare providers, and vaccine misinformation are often responsible for low immunization rates. This review summarizes the impact of vaccine-preventable illness in those with CLD, updated vaccine guidelines, seroconversion rates in the vaccinated, and barriers faced by healthcare professionals in immunizing those with liver disease.

Live virus vaccination following pediatric liver transplantation: Outcomes from two academic children's hospitals

Pediatric liver transplant (LT) recipients are often transplanted at a young age, precluding them from receiving live virus vaccinations (LVV) such as varicella (VZV) vaccine and measles, mumps and rubella. This places them at profound risk for vaccine preventable illness. We sought to detail safety of vaccination. This was a retrospective cohort study of pediatric LT recipients at two children's hospitals. Among 204 LT recipients included in the study, 97 received at least one LVV after LT. Six patients who did not receive LVV after transplant had evidence of vaccine-preventable infection following vaccination (one disseminated VZV disease, five VZV-related rash), while one patient who received LVV after transplant developed a diffuse VZV-related rash. Rejection rates were the same between those that did and did not receive a live virus vaccine post-transplant. There were no serious adverse events caused by vaccination post-transplant. LVV following LT was safe at our two institutions, although there exist limitations in our study due to its retrospective study design. Larger scale studies should be performed to evaluate the effectiveness of LVV in relation to immunosuppression.

Long-Term Varicella Zoster Virus Immunity in Paediatric Liver Transplant Patients Can Be Achieved by Booster Vaccinations—A Single-Centre, Retrospective, Observational Analysis

Varicella is one of the most common vaccine-preventable infections after paediatric solid organ transplantation; thus, vaccination offers simple and cheap protection. However, children with liver disease often progress to liver transplantation (LT) before they reach the recommended vaccination age. As a live vaccine, varicella zoster virus (VZV) vaccination after transplantation is controversial; however, many case series demonstrate that vaccination may be safe and effective in paediatric liver transplant recipients. Only limited data exists describing long-term vaccination response in such immunocompromised patients. We investigated retrospectively vaccination response in paediatric patients before and after transplantation and describe long-term immunity over ten years, including the influence of booster-vaccinations. In this retrospective, single-centre study, 458 LT recipients were analysed between September 2004 and June 2021. Of these, 53 were re-transplantations. Patients with no available vaccination records and with a history of post-transplant lymphoproliferative disease, after hematopoietic stem cell transplantation and clinical chickenpox were excluded from this analysis (n = 198). In total, data on 207 children with a median annual follow-up of 6.2 years was available: 95 patients (45.9%) were unvaccinated prior to LT. Compared to healthy children, the response to vaccination, measured by seroconversion, is weaker in children with liver disease: almost 70% after one vaccination and 93% after two vaccinations. One year after transplantation, the mean titres and the number of children with protective antibody levels (VZV IgG ≥ 50 IU/L) decreased from 77.5% to 41.3%. Neither diagnosis, gender, nor age were predictors of vaccination response. Booster-vaccination was recommended for children after seroreversion using annual titre measurements and led to a significant increase in mean titre and number of protected children. Response to vaccination shows no difference from monotherapy with a calcineurin inhibitor to intensified immunosuppression by adding prednisolone or mycophenolate mofetil. Children with liver disease show weaker seroconversion rates to VZV vaccination compared to healthy children. Therefore, VZV-naïve children should receive basic immunization with two vaccine doses as well as those vaccinated only once before transplantation. An average of 2–3 vaccine doses are required in order to achieve a long-term seroconversion and protective antibody levels in 95% of children.

A Smartphone App to Increase Immunizations in the Pediatric Solid Organ Transplant Population: Development and Initial Usability Study

Background

Vaccine-preventable infections result in significant morbidity, mortality, and costs in pediatric transplant recipients. However, at the time of transplant, less than 20% of children are up-to-date for age-appropriate immunizations that could prevent these diseases. Smartphone apps have the potential to increase immunization rates through their ability to provide vaccine education, send vaccine reminders, and facilitate communication between parents and a multidisciplinary medical group.

Objective

The aim of this study was to describe the development of a smartphone app, Immunize PediatricTransplant, to promote pretransplant immunization and to report on app functionality and usability when applied to the target population.

Methods

We used a mixed methods study design guided by the Mobile Health Agile Development and Evaluation Lifecycle. We first completed a formative research including semistructured interviews with transplant stakeholders (12 primary care physicians, 40 parents or guardians of transplant recipients, 11 transplant nurse coordinators, and 19 transplant subspecialists) to explore the acceptability of an immunization app to be used in the pretransplant period. Based on these findings, CANImmunize Inc developed the Immunize PediatricTransplant app. We next held 2 focus group discussions with 5-6 transplant stakeholders/group (n=11; 5 parents of transplant recipients, 2 primary care physicians, 2 transplant nurse coordinators, and 2 transplant subspecialists) to receive feedback on the app. After the app modifications were made, alpha testing was conducted on the functional prototype. We then implemented beta testing with 12 stakeholders (6 parents of transplant recipients, 2 primary care doctors, 2 transplant nurse coordinators, and 2 transplant subspecialists) to refine the app through an iterative process. Finally, the stakeholders completed the user version of the Mobile Application Rating Scale (uMARS) to assess the functionality and quality of the app.

Results

A new Android- and Apple-compatible app, Immunize PediatricTransplant, was developed to improve immunization delivery in the pretransplant period. The app contains information about vaccine use in the pretransplant period, houses a complete immunization record for each child, includes a communication tool for parents and care providers, and sends automated reminders to parents and care providers when immunizations are due. During usability testing, the stakeholders were able to enter a mock vaccine record containing 16 vaccines in an average of 8.1 minutes (SD 1.8) with 87% accuracy. The stakeholders rated engagement, functionality, aesthetics, and information quality of the app as 4.2/5, 4.5/5, 4.6/5, and 4.8/5, respectively. All participants reported that they would recommend this app to families and care teams with a child awaiting solid organ transplant.

Conclusions

Through a systematic, user-centered, agile, iterative approach, the Immunize PediatricTransplant app was developed to improve immunization delivery in the pretransplant period. The app tested well with end users. Further testing and agile development among patients awaiting transplant are needed to understand real-world acceptability and effectiveness in improving immunization rates in children awaiting transplant.

Vaccination in pediatric solid organ transplant: A primer for the immunizing clinician

Pediatric solid organ transplant (SOT) recipients are at a uniquely elevated risk for vaccine preventable illness (VPI) secondary to a multitude of factors including incomplete immunization at the time of transplant, inadequate response to vaccines with immunosuppression, waning antibody titers observed post-SOT, and uncertainty among providers on the correct immunization schedule to utilize post-SOT. Multiple guidelines are in existence from the Infectious Diseases Society of America and the American Society of Transplantation, which require use in adjunct with additional published references. We summarize the present state of SOT vaccine recommendations from relevant resources in tandem with the Centers for Disease Control and Prevention Advisory Committee on Immunization Practices guidance utilizing both routine and rapid catch-up schedules. The purpose of this all-inclusive review is to provide improved clarity on the most optimal pre- and post-transplant vaccine management within a one-stop-shop for the immunizing clinician. This article is protected by copyright. All rights reserved.

Pre-transplant vaccination compliance in adult heart and lung transplant recipients

BACKGROUND

Vaccine preventable diseases can affect solid organ transplant recipients post-transplant. Therefore, the administration of vaccines and assessment of serologic response should be prioritized in the pre-transplant period.

METHODS

This single-center, retrospective study included 349 adult heart or lung transplant candidates between December 1, 2017 and November 30, 2019. We describe vaccination or serologic status for hepatitis A, hepatitis B, tetanus, pneumococcal, influenza, and other recommended vaccinations among heart or lung transplant candidates.

RESULTS

Eighty-two heart transplant candidates (91%) and 77 lung transplant candidates (30%) received an ID consult prior to transplant. More patients completed the pneumococcal series (66.7% vs. 28.6%, P = .045) in the heart transplant group that received an ID consult. In the lung transplant group, patients with an ID consult demonstrated higher rates of immunity to hepatitis A (84.4% vs. 72.9%, P = .047), hepatitis B (75.3% vs. 56.9%, P = .005), and measles (71.4% vs. 52.5%, P = .005) compared to those without.

CONCLUSIONS

Our results demonstrate the value of consulting ID and administering vaccinations in the early evaluation phase, prior to transplant listing. Opportunities remain to better optimize vaccination rates prior to transplant in heart and lung transplant candidates.

Under-Vaccination in Pediatric Liver Transplant Candidates with Acute and Chronic Liver Disease—A Retrospective Observational Study of the European Reference Network TransplantChild

Infection is a serious concern in the short and long term after pediatric liver transplantation. Vaccination represents an easy and cheap opportunity to reduce morbidity and mortality due to vaccine-preventable infection. This retrospective, observational, multi-center study examines the immunization status in pediatric liver transplant candidates at the time of transplantation and compares it to a control group of children with acute liver disease. Findings show only 80% were vaccinated age-appropriately, defined as having received the recommended number of vaccination doses for their age prior to transplantation; for DTP-PV-Hib, less than 75% for Hepatitis B and two-thirds for pneumococcal conjugate vaccine in children with chronic liver disease. Vaccination coverage for live vaccines is better compared to the acute control group with 81% versus 62% for measles, mumps and rubella (p = 0.003) and 65% versus 55% for varicella (p = 0.171). Nevertheless, a country-specific comparison with national reference data suggests a lower vaccination coverage in children with chronic liver disease. Our study reveals an under-vaccination in this high-risk group prior to transplantation and underlines the need to improve vaccination.

Immunization status and hospitalization for vaccine-preventable and non-vaccine-preventable infections in liver-transplanted children

BACKGROUND

Infections and associated morbidity and mortality may be more frequent in children who have undergone liver transplant than in healthy children. Immunization strategies to prevent vaccine-preventable infections (VPIs) can effectively minimize this infection burden. However, data on age-appropriate immunization and VPIs in children after liver transplant in Asia are limited.

AIM

To evaluate the immunization status, VPIs and non-VPIs requiring hospitalization in children who have undergone a liver transplant.

METHODS

The medical records of children who had a liver transplant between 2004 and 2018 at King Chulalongkorn Memorial Hospital (Bangkok, Thailand) were retrospectively reviewed. Immunization status was evaluated via their vaccination books. Hospitalization for infections that occurred up to 5 years after liver transplantation were evaluated, and divided into VPIs and non-VPIs. Hospitalizations for cytomegalovirus and Epstein-Barr virus were excluded. Severity of infection, length of hospital stay, ventilator support, intensive care unit requirement, and mortality were assessed.

RESULTS

Seventy-seven children with a mean age of 3.29 ± 4.17 years were included in the study, of whom 41 (53.2%) were female. The mean follow-up duration was 3.68 ± 1.45 years. Fortyeight children (62.3%) had vaccination records. There was a significant difference in the proportion of children with incomplete vaccination according to Thailand’s Expanded Program on Immunization (52.0%) and accelerated vaccine from Infectious Diseases Society of America (89.5%) (P < 0.001). Post-liver transplant, 47.9% of the children did not catch up with age-appropriate immunizations. There were 237 infections requiring hospitalization during the 5 years of follow-up. There were no significant differences in hospitalization for VPIs or non-VPIs in children with complete and incomplete immunizations. The risk of serious infection was high in the first year after receiving a liver transplant, and two children died. Respiratory and gastrointestinal systems were common sites of infection. The most common pathogens that caused VPIs were rotavirus, influenza virus, and varicella-zoster virus.

CONCLUSION

Incomplete immunization was common pre- and post-transplant, and nearly all children required hospitalization for non-VPIs or VPIs within 5 years post-transplant. Infection severity was high in the first year post-transplant.

Barriers to Pretransplant Immunization: A Qualitative Interview Study of Pediatric Solid Organ Transplant Stakeholders

OBJECTIVES

To describe the experiences and beliefs of pediatric transplant stakeholders regarding factors that contribute to low pretransplant immunization rates.

STUDY DESIGN

Semistructured interviews were conducted with transplant team members (hepatologists, cardiologists, nephrologists, transplant nurse coordinators, and transplant infectious diseases physicians), primary care physicians, and parents of heart, liver, and kidney transplant recipients at 3 geographically diverse large pediatric transplant centers in the US. Interviews were conducted between July 2017 and February 2020 until thematic saturation was reached within each stakeholder subgroup. Content analysis methodology was used to identify themes.

RESULTS

Stakeholders participated in 30- to 60-minute interviews (16 transplant subspecialists, 3 transplant infectious diseases physicians, 11 transplant nurse coordinators, 12 primary care physicians, and 40 parents). Five central themes emerged: (1) gaps in knowledge about timing and safety of pretransplant immunizations, (2) lack of communication, coordination, and follow-up between team members regarding immunizations, (3) lack of centralized immunization records, (4) subspecialty clinic functioning as the medical home for transplant candidates but unable to provide all needed immunizations, and (5) differences between organ type in prioritization and completion of pretransplant immunization.

CONCLUSIONS

There are multiple factors that contribute to low immunization rates among pediatric transplant candidates. New tools are needed to overcome these barriers and increase immunization rates in transplant candidates.

The Importance of Prioritizing Pre and Posttransplant Immunizations in an Era of Vaccine Refusal and Epidemic Outbreaks

Vaccine-preventable infections are occurring at epidemic rates both nationally and internationally. At the same time, rates of vaccine hesitancy and refusal are increasing across the country leading to decreased herd immunity. For immunosuppressed transplant recipients, this situation poses great risk. Currently, 1 in 6 pediatric solid organ transplant recipients is hospitalized with a vaccine-preventable infection in the first 5 years posttransplant. For many recipients, these infections result in significant morbidity, mortality, and increased hospitalization costs. Surprisingly, despite this risk many transplant recipients are not up-to-date on age appropriate immunizations at the time of transplant and thereafter. As a transplant community, we must prioritize immunizations in both pre and posttransplant care. Research is needed to understand how to monitor immune response to vaccines in immunosuppressed patients and when to optimally immunize patients posttransplant. Finally, recommendations about administration of live vaccines posttransplant may need to be reevaluated in the setting of measles outbreaks and decreased herd immunity.

Underimmunization of the solid organ transplant population: An urgent problem with potential digital health solutions

Solid organ transplant recipients are at risk for potentially life-threatening infections due to lifelong immunosuppression. Vaccine-preventable infections result in graft injury, morbidity, mortality, and significantly increased medical costs. Unfortunately, the majority of transplant recipients continue to be underimmunized at the time of transplant and thereafter. Given the rising rates of vaccine hesitancy and refusal in the general population, transplant recipients can no longer rely on herd immunity to protect them from vaccine-preventable infections. Novel tools are desperately needed to overcome transplant-specific immunization barriers to improve immunization rates in this high-risk population. Digital health technologies may offer a solution by addressing transplant-specific barriers: specifically, providing accurate information about vaccine safety, efficacy, and timing in the pre- and posttransplant periods; making a complete immunization record universally available and easily accessible; enabling communication between patients and multiple providers; and providing automated vaccine reminders to both patients and providers when vaccines are due using transplant-specific immunization guidelines. Digital health has transformed health care by empowering patients with their own health information and connecting patients, their providers, and public health officials. In doing so, it offers a potential platform to address and overcome the problem of underimmunization in the transplant population.

Under-immunization of pediatric transplant recipients: a call to action for the pediatric community

Vaccine-preventable infections (VPIs) are a common and serious complication following transplantation. One in six pediatric solid organ transplant recipients is hospitalized with a VPI in the first 5 years following transplant and these hospitalizations result in significant morbidity, mortality, graft injury, and cost. Immunizations are a minimally invasive, cost-effective approach to reducing the incidence of VPIs. Despite published recommendations for transplant candidates to receive all age-appropriate immunizations, under-immunization remains a significant problem, with the majority of transplant recipients not up-to-date on age-appropriate immunizations at the time of transplant. This is extremely concerning as the rate for non-medical vaccine exemptions in the United States (US) is increasing, decreasing the reliability of herd immunity to protect patients undergoing transplant from VPIs. There is an urgent need to better understand barriers to vaccinating this population of high-risk children and to develop effective interventions to overcome these barriers and improve immunization rates. Strengthened national policies requiring complete age-appropriate immunization for non-emergent transplant candidates, along with improved multi-disciplinary immunization practices and tools to facilitate and ensure complete immunization delivery to this high-risk population, are needed to ensure that we do everything possible to prevent infectious complications in pediatric transplant recipients.

Immunization Status at the Time of Liver Transplant in Children and Adolescents

This study characterizes the percentage of pediatric patients undergoing liver transplant who were up to date for their age on immunizations at the time of transplant and risk factors for underimmunization.

It takes a village: primary care of the pediatric liver transplant recipient

PURPOSE OF REVIEW

Long-term survival is now the rule rather than the exception for infants and children who undergo liver transplantation for end-stage liver disease, metabolic liver conditions and a variety of other indications. Pediatricians and primary care providers play vital roles in the care and management of this patient population. The purpose of this review is to highlight key aspects important to the care of the pediatric liver transplant recipient.

RECENT FINDINGS

Significant advances in immunosuppressive therapies and surgical techniques have contributed to improved graft and patient survival rates, shifting the focus beyond immediate survival to strategies to minimize comorbidities related to long-term immunosuppression during growing years, attend to patient and parent-reported outcomes and enhance quality of life. A multidisciplinary approach allows for monitoring and surveillance of both routine (growth, nutritional rehabilitation, cognitive development, mental and psychosocial health, contraception and daily activities) and transplant-related (adverse effects of immunosuppression, susceptible infections, extra-hepatic systems, transition from childhood to adolescence to adulthood) themes.

SUMMARY

Effective communication between the primary care physician and the transplant team is imperative for optimizing best outcomes. The primary care provider should be aware of the multifacet nature of posttransplant management, which includes medication regimens, common complications and infections.

Incidence of Hospitalization for Vaccine-Preventable Infections in Children Following Solid Organ Transplant and Associated Morbidity, Mortality, and Costs

IMPORTANCE

Pediatric transplant recipients are at risk for vaccine-preventable infections owing to immunosuppression, suboptimal response to vaccines before and after transplant, and potential underimmunization if transplant occurred early in life. However, the incidence and burden of illness from vaccine-preventable infections in this population is unknown.

OBJECTIVES

To evaluate in pediatric solid organ transplant recipients the number of hospitalizations for vaccine-preventable infections in the first 5 years after transplant and to determine the associated morbidity, mortality, and costs.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study from January 1, 2004, to December 31, 2011, with 5 years of follow-up per participant (unless they died during the study period). The participants of this multicenter study through the Pediatric Health Information System were solid organ transplant recipients who were younger than 18 years at the time of transplant. Analysis began in July 2017.

EXPOSURES

Transplant.

MAIN OUTCOMES AND MEASURES

Hospitalizations for a vaccine-preventable infection during the first 5 years after transplant were ascertained using International Classification of Diseases, Ninth Revision, and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, clinical modification diagnosis codes. Data were collected on clinical care, outcomes, and costs during these hospitalizations.

RESULTS

Of 6980 transplant recipients identified, there were 3819 boys (54.7%), and the mean (SD) age at transplant was 8 (6.2) years. Overall, 1092 patients (15.6%) had a total of 1471 cases of vaccine-preventable infections. There were 187 of 1471 cases (12.7%) that occurred during transplant hospitalization. The case fatality rate was 1.7% for all infections. Excluding infections that occurred during transplant hospitalization (when all patients go to the intensive care unit), 213 of 1257 patients (17.0%) were hospitalized with a vaccine-preventable infection requiring intensive care. In multivariable analysis, age younger than 2 years at time of transplant and receipt of a lung, heart, intestine, or multivisceral organ were positively associated with increased risk of a hospitalization from a vaccine-preventable infection.Transplant hospitalizations complicated by vaccine-preventable infections were $120 498 more expensive (median cost) than transplant hospitalizations not complicated by vaccine-preventable infections.

CONCLUSIONS AND RELEVANCE

Hospitalization for vaccine-preventable infections occurred in more than 15% of solid organ transplant recipients in the first 5 years after transplant at a rate of up to 87 times higher than in the general population. There was significant morbidity, mortality, and costs from these infections, demonstrating the importance of immunizing all transplant candidates and recipients. Further research on improving immunization delivery, preventing nosocomial infections, and monitoring response to vaccines in the transplant population is needed.

Hospitalizations for Respiratory Syncytial Virus and Vaccine-Preventable Infections in the First 2 Years After Pediatric Liver Transplant

OBJECTIVES

To examine in liver transplant recipients at centers participating in the Pediatric Health Information System dataset the number of hospitalizations for respiratory syncytial virus (RSV) and vaccine-preventable infections (VPIs) in the first 2 years after transplantation, morbidity and mortality associated with these hospitalizations, and costs associated with these hospitalizations.

STUDY DESIGN

A retrospective cohort study of patients <18 years of age who underwent liver transplantation at a Pediatric Health Information System center between January 1, 2004, and December 31, 2012. Hospitalizations for RSV/VPIs during the first 2 years post-transplant were ascertained using International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. Data were collected on clinical care, outcomes, and costs during these hospitalizations.

RESULTS

There were 2554 liver transplant recipients identified; 415 patients (16.3%) had 544 cases of RSV/VPIs. RSV, rotavirus, and influenza were the most common infections resulting in hospitalization. Ninety-two patients (3.6%) had RSV/VPI during their transplant hospitalization. Transplant hospitalizations complicated by RSV/VPI were longer (44 days vs. 21 days; P < .001), had higher rejection rates (37% vs. 26%; P = .02), and were more expensive ($259 697 vs. $190 860; P < .001). Multivariate analyses identified age <2 years at transplant (P < .001) and multivisceral recipient (P = .04) as predictors of a hospitalization for RSV.

CONCLUSIONS

VPIs occurred in 1 of 6 liver transplant recipients in the first 2 years post-transplant, a significantly higher rate than in the general pediatric population. These hospitalizations had substantial morbidity, mortality, and costs, demonstrating the importance of vaccinating patients before transplantation.