Evaluation of the vaccination status in pediatric renal transplant recipients

Impact of catch-up vaccinations on anti-HLA antibody response in pediatric kidney transplant candidates

BACKGROUND

Efforts have been concentrated on improving vaccination administration during the pretransplant evaluation period. However, concern for human leukocyte antigen (HLA) sensitization subsequent to vaccination exists.

METHODS

A retrospective review of pediatric kidney transplant candidates (PKTCs) ≤18 years old who had received vaccinations between February 1, 2017 and November 30, 2019 was conducted. Emergence of de novo anti-HLA antibody (HLA-Ab) 3-4 weeks postvaccinations detected by the Luminex single antigen bead assay (SAB) was evaluated. Outcomes assessed included change in the HLA-Ab mean fluorescence intensity (MFI) ≥25% from baseline, and change in preexisting HLA-Ab MFI strength, categorized as weak: 1000-2999; moderate: 3000-9999; and strong: ≥10 000.

RESULTS

Sixty vaccinations were administered to 14 patients. Forty-one potential de novo HLA-Ab were detected in five patients. After additional antibody panel testing, 5/41 potential de novo HLA-Ab were determined to be HLA specific; the remaining 36 were deemed nonspecific. The 5 de novo HLA-Ab were observed in three patients and were deemed weak antibody (Ab). Median MFI showed a significant increase for nonspecific Ab, but not de novo HLA-Ab. Median MFI values were deemed transient at 7-10 week follow-up. No HLA-donor-specific Ab developed posttransplant in the patients who developed de novo HLA-Ab.

CONCLUSION

Vaccination resulted in a transient increase in non-HLA-specific Ab. The majority of responses were non-HLA specific, hypothesized to be related to denatured antigens on single antigen beads. These data suggest limited clinical impact of vaccinations on the emergence of de novo HLA-Ab.

Considering a COVID-19 vaccine mandate for pediatric kidney transplant candidates

The world continues to face the effects of the SARS-CoV-2 pandemic. COVID-19 vaccines are safe and effective in protecting recipients, decreasing the risk of COVID-19 acquisition, transmission, hospitalization, and death. Transplant recipients may be at greater risk for severe SARS-CoV-2 infection. As a result, transplant programs have begun instituting mandates for COVID-19 vaccine for transplant candidacy. While the question of mandating COVID-19 vaccine for adult transplant candidates has garnered attention in the lay and academic press, these discussions have not explicitly addressed children who may be otherwise eligible for kidney transplants. In this paper we seek to examine the potential ethical justifications of a COVID-19 vaccine mandate for pediatric kidney transplant candidacy through an examination of relevant ethical principles, analogous cases of the use of mandates, differences between adult and pediatric kidney transplant candidates, and the role of gatekeeping in transplant vaccine mandates. At present, it does not appear that pediatric kidney transplant centers are justified to institute a COVID-19 vaccine mandate for candidates. Finally, we will offer suggestions to be considered prior to the implementation of a COVID-19 vaccine mandate.

Gaps in knowledge about the vaccine coverage of immunocompromised children: a scoping review

Immunocompromised children are at increased risk of severe illness from vaccine-preventable infections. However, inadequate vaccine coverage remains a concern. This scoping review sought to determine the current state of knowledge regarding vaccine coverage of immunocompromised children. Bibliographic databases were searched for primary research from any year. Data were analyzed quantitatively and narratively. Ninety-seven studies met inclusion criteria. The most commonly studied vaccines were pneumococcal (n = 46), influenza (n = 44), diphtheria/tetanus/pertussis/poliomyelitis/Haemophilus influenzae type B/hepatitis B-containing (n = 36), and measles- and/or mumps- and/or rubella-containing (n = 29). Immunocompromising conditions studied included cancer/stem cell transplants (n = 24), solid organ transplants (n = 23), sickle cell disease (n = 21), immunosuppressive therapy (n = 14), human immunodeficiency virus (n = 12), splenectomy (n = 4), and primary immunodeficiency (n = 2). As more children are treated with immunosuppressive therapies, it is critical to identify whether they are being appropriately vaccinated for age and condition. We identified gaps in the current state of knowledge for specific vaccine types in specific immunocompromised populations.

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.

Immunization in end stage renal disease: The perception of waiting list patients

BACKGROUND

The number of patients with chronic kidney disease is increasing worldwide, as well as the number of patients in kidney transplant waiting lists. In order to prevent infections related to immunosuppressive therapy, immunization guidelines for CKD patients before transplantation have been proposed. The aim of the present study was to evaluate adherence to immunization in a cohort of CKD patients in transplant waiting list and their renal replacement therapy clinics.

METHODS

CKD patients older than 18 years old, receiving renal replacement therapy longer than 12 months and included in kidney transplant waiting list at University of Campinas (Unicamp) were enrolled.

RESULTS

From February 2014 to December 2015, 105 patients fulfilled the inclusion criteria. Complete hepatitis B vaccination was observed in 73% and influenza vaccine in 67%. None of the other vaccine protocols reached 50% of coverage. Patients receiving immunization at primary health units presented higher coverage for diphtheria, tetanus (dT), measles, mumps, rubella (MMR), and hepatitis B vaccines, while patients immunized at renal replacement therapy clinics showed higher prevalence of pneumococcus (pneumo23).

CONCLUSION

The low rates of immunization could reflect the RRT's clinics knowledge about the vaccines guidelines and its application on daily care. We suggest an integration between transplant center and RRT clinics, through lectures, periodic checking of vaccination cards, and easy to follow guidelines in order to provide a better vaccine coverage and to obtain higher immunization rates.

Incomplete vaccination coverage in European children with end-stage kidney disease prior to renal transplantation

BACKGROUND

Because infections constitute a major cause of morbidity and mortality in paediatric renal allograft recipients, avoidance of preventable systemic infections by vaccination before transplantation is of utmost importance. However, data on the completeness of vaccinations and factors associated with incomplete vaccination coverage are scarce.

METHODS

Within the framework of the Cooperative European Paediatric Renal Transplant Initiative (CERTAIN), we therefore performed a multi-centre, multi-national, retrospective study investigating the vaccination coverage before transplantation of 254 European children with end-stage renal disease (mean age 10.0 ± 5.6 years).

RESULTS

Only 22 out of 254 patients (8.7%) presented complete vaccination coverage. In particular, the respective vaccination coverage against human papillomavirus (27.3%), pneumococci (42.0%), and meningococci (47.9%) was low. Patients with complete pneumococcal vaccination coverage had numerically less lower respiratory tract infections during the first 3 years post-transplant than children without vaccination or with an incomplete status (16.4% vs 27.7%, p = 0.081). Vaccine-preventable diseases post-transplant were 4.0 times more frequently in unvaccinated than in vaccinated patients. Factors associated with an incomplete vaccination coverage were non-Caucasian ethnicity (OR 9.21, p = 0.004), chronic dialysis treatment before transplantation (OR 6.18, p = 0.001), and older age at transplantation (OR 1.33, p < 0.001).

CONCLUSIONS

The vaccination coverage in paediatric kidney transplant candidates is incomplete. Paediatric nephrologists, together with primary-care staff and patients' families, should therefore make every effort to improve vaccination rates before kidney transplantation.

Impact of a pharmacist-led vaccine recommendation program for pediatric kidney transplant candidates

Pediatric transplant recipients commonly have deficient vaccination status at the time of transplantation. Utilizing transplant pharmacists to improve vaccination rates has not previously been described. This single-center, retrospective study evaluated the impact of transplant pharmacist interventions on the completion rate of vaccination schedules at time of kidney transplant. Patients who received pharmacist-led vaccination recommendations prior to transplant were compared to patients without pharmacist recommendations. Forty-seven pediatric patients were included: 24 intervention patients and 23 control patients. The median percentage of up-to-date vaccinations at time of transplant was significantly higher in intervention group (91%; IQR 86%-100%) vs. control group (80%; IQR 71%-80%) (P<.0001). The median change in up-to-date vaccinations from time of evaluation to time of transplant was also significantly higher in the intervention group (7.5%) compared to the control group (0%) (P<.0001). There was no difference in live vaccination rates. No patients in either group were readmitted for a vaccine-preventable disease within 6 months post-transplant. With pharmacist intervention, significantly more patients were up to date with vaccination schedules at the time of transplant. These results suggest that a transplant pharmacist may serve as a valuable resource to increase vaccination schedule compliance between time of evaluation and transplantation.

Vaccination of adolescents with chronic medical conditions: Special considerations and strategies for enhancing uptake

Adolescents with chronic medical conditions (CMCs), a growing population worldwide, possess a wide array of preventive health care needs. Vaccination is strongly recommended for the vast majority of these adolescents given their increased risk of vaccine preventable infection and associated complications. Not only should they receive routine vaccines, but some also require additional vaccines. Despite these guidelines, evidence suggests that adolescents with CMCs often fail to receive needed vaccines. Many factors contribute to this under-immunization, including lack of knowledge among parents and providers and suboptimal coordination of primary and subspecialty care. This review describes current vaccination recommendations for these adolescents as well as recent data related to infection risk, vaccine efficacy and safety, vaccination coverage, and the unique multilevel factors impacting uptake in this population. It also discusses strategies for improving coverage levels and reducing missed vaccination opportunities, with a particular focus on technology-based interventions.

Vaccination coverage and risk factors for incomplete vaccination in children with recurrent wheeze

AIM

To determine the possible impact of recurrent wheeze on immunisation status in the first three years of life.

METHOD

A cross-sectional case control study of 288 children less than three years of age with a history of recurrent wheezing, hospitalised at a single centre for wheeze; and a control group of 190 children with no prior history of wheezing. Vaccination charts of all children were analysed according to the National Immunisation Schedule. Additionally, some associated data were collected through a questionnaire to the parents.

RESULTS

Children with recurrent wheezing during the first three years of life were less likely to be vaccinated against BCG (Bacillus-Calmette-Guerin), hepatitis B, Hib (Haemophilus influenza type B), and MMR (Measles, Mumps, Rubella) (p < 0.001). A significant inverse association was also found between the number of wheezy episodes and the number of vaccine doses received. The odds ratio of incomplete vaccination in children with recurrent wheeze was 10.6 (95% CI, 2.96 to 38.1).

CONCLUSION

Children under three years of age with recurrent wheeze run a high risk of incomplete immunisation. Efforts should be therefore made to insure that such children receive adequate vaccination.

Vaccination coverage in immunosuppressed patients: results of a regional health services research study

BACKGROUND

Patients with chronic inflammatory diseases are at elevated risk of infections that can be prevented by vaccination. This elevated risk is due not just to these patients' primary illnesses, but also to the immunosuppressive treatment that they often receive. We studied the vaccination rate in a random sample of patients with two types of inflammatory bowel disease (IBD), namely, Crohn's disease and ulcerative colitis. In particular, we asked unvaccinated patients why they had re-fused the vaccine.

METHODS

From April to September 2009, we gave a 38-item questionnaire to 203 consecutive patients with IBD (57% with Crohn's disease, 63% female, median age 36 years) who had not received vaccination counseling for at least one year, and inspected the patients' vaccination cards. We compared the findings to the current recommendations of the German Federal Standing Committee on Vaccination (Ständige Impfkommission).

RESULTS

83% of the patients had a vaccination card. Substantial deficiencies in vaccination were found. Only 67% of the patients had been immunized against tetanus in the previous 10 years, and only 21% against pertussis. Only 28% were vaccinated against seasonal influenza in 2008, and only 9% had ever received anti-pneumococcal vaccine. A subgroup analysis in which we compared 39 patients taking TNF-blockers to 67 patients who never had any type of immunosuppressive treatment revealed no difference in vaccination rates. 80% of all patients said they were willing to receive all of the officially recommended vaccinations. 22% of all patients said they avoided vaccinations for fear of side effects, while 15% said they did so because their immune system was supposedly "not intact", and 9% because they feared vaccination would worsen their IBD.

CONCLUSION

In this random sample, the vaccination rate fell far behind the recommendations. In particular, there was a marked discrepancy between patients' willingness to be vaccinated and the actual provision of vaccination. These findings imply that physicians need to be more aware of the possibly inadequate vaccination state of their immunosuppressed patients.

Determinants of vaccine immunity in the cohort of human immunodeficiency virus-infected children living in Switzerland

BACKGROUND

Human immunodeficiency virus (HIV)-infected children are at increased risk of infections caused by vaccine preventable pathogens, and specific immunization recommendations have been issued.

METHODS

A prospective national multicenter study assessed how these recommendations are followed in Switzerland and how immunization history correlates with vaccine immunity.

RESULTS

Among 87 HIV-infected children (mean age: 11.1 years) followed in the 5 Swiss university hospitals and 1 regional hospital, most (76%) had CD4 T cells >25%, were receiving highly active antiretroviral treatment (79%) and had undetectable viral load (60%). Immunization coverage was lower than in the general population and many lacked serum antibodies to vaccine-preventable pathogens, including measles (54%), varicella (39%), and hepatitis B (65%). The presence of vaccine antibodies correlated most significantly with having an up-to-date immunization history (P<0.05). An up-to-date immunization history was not related to age, immunologic stage, or viremia but to the referral medical center.

CONCLUSIONS

All pediatricians in charge of HIV-infected children are urged to identify missing immunizations in this high-risk population.

Vaccination status in pediatric liver transplant candidates

Infection is a recognized and potentially serious complication in children following solid organ transplantation. This problem is particularly important for young children undergoing any organ transplantation who often have not completed standard childhood immunizations at the time of transplantation and who are therefore at risk for vaccine-preventable infections. To evaluate the vaccination status in liver transplant candidates, vaccination charts of 100 patients who were referred to Organ Transplant Center of Nemazee Hospital were reviewed and the vaccination status considered appropriate according to the recommendation of NIP and the patients' age. Fifty-eight percent of patients were completely vaccinated for HBV, 85% for OPV, 97% for BCG, 63% for DTP, and 58% of the patients were completely vaccinated for MMR. We concluded that the vaccination charts should be periodically reviewed and updated to prevent the vaccine-preventable disease in liver transplant candidates not only before but also after transplant. Every effort should be made to assure that candidates are immunized early in the course of their disease. Also it may be indicated to recommend a special guideline for immunization of liver transplant candidates and add other vaccines such as Haemophilus influenzae and Streptococcus pneumoniae vaccine to their vaccination program.

Immunizations in patients with inflammatory bowel disease

Patients receiving immunosuppressive therapies may be at increased risk for complications of vaccine preventable diseases, including influenza, varicella, and pneumococcus. However, studies suggest that patients with chronic illness may be inadequately immunized. In part, this is because of a paucity of formal vaccine studies in immune compromised populations. This review discusses the methods one uses to assess vaccine efficacy and provides an update on currently known data on the vaccine antibody responses in immune compromised hosts. Currently published studies suggest that influenza vaccine can be safely administered to patients with IBD on immunosuppression, and is effective in the majority of patients. Further formal studies with other inactivated vaccines (e.g., pneumococcal vaccine, meningitis vaccine) should be conducted. While some studies in immune compromised hosts suggest the live attenuated varicella vaccine can be given without adverse events, administration of this vaccine in patients on immunosuppression remains controversial.