COVID-19 infection in pediatric solid organ transplant patients

SARS-CoV-2-Specific Antibodies in Pediatric Solid Organ Transplant Recipients: Benefits of Additional Vaccine Doses

BACKGROUND

Limited data are available regarding the development and durability of immune responses following COVID-19 infection or vaccination in pediatric solid-organ transplant (SOT) recipients.

METHODS

Renal, liver, or intestinal transplant recipients < 21 years of age followed at Seattle Children's Hospital were enrolled from August 2020 to May 2021. Blood samples were collected at ~6-month intervals for up to 3 years and tested for antinucleocapsid (N) antibodies. COVID-19 vaccination data were collected from the Washington State Immunization Information System and/or the medical record. Semi-quantitative anti-S IgG testing was performed on all postvaccine samples using the Abbott Architect platform. We further evaluated a subset of postvaccine samples using variant-specific quantitative binding (Meso Scale Discovery, MSD) immunoassays and pseudovirus-neutralization assays. Antibody levels were compared over time and by vaccine category.

RESULTS

We followed 83 SOT recipients for a median of 12.5 months (IQR 7.0, 28.3). Overall, 16 (19.3%) participants had evidence of SARS-CoV-2 infection based on anti-N antibody detection. Forty-six (55%) participants had a blood sample collected > 14 days after receipt of a vaccination. Serum IgG to spike antigens (anti-S antibody) increased following vaccination and increased with the number of vaccine doses received as assessed by both the Abbott and MSD assays. Neutralizing activity was significantly lower against the Omicron subvariants compared to the ancestral strain.

CONCLUSION

Pediatric SOT recipients demonstrated strong antibody responses following SARS-CoV-2 vaccination, with higher anti-S antibody responses following > 2 doses of vaccine. Our study offers unique longitudinal immune response data in this vulnerable patient population.

Humoral and cellular response to SARS-CoV-2 mRNA vaccine in paediatric heart transplant recipients

Objective

The aim of this prospective cohort study is to analyse the humoral and cellular vaccine responses in paediatric heart transplant recipients (HTR, n = 12), and compare it with the response in healthy controls (HC, n = 14). All participants were 5-18 years old and vaccinated with mRNA vaccine against SARS-CoV-2 between December 2021 and May 2022.

Methods

The humoral response was measured by quantifying antibody titers against SARS-CoV-2 spike protein (anti-S). The T-lymphocyte phenotype and SARS-CoV2-specific CD4+ and CD8+ T-cell response was studied by multiparametric flow cytometry through peripheral blood mononuclear cells by the quantification of degranulation markers (CD107a) and intracellular cytokines (IFN-γ, TNF-α and IL-2) after in vitro stimulation with SARS-CoV-2 peptides from structural proteins (S, M, N, E) and non-structural viral proteins.

Results

After vaccination, humoral response was found in all HTR, although they showed lower levels of anti-S IgG compared to HC (p = 0.003). However, in terms of cellular response, no significant differences were obtained in the prevalence of responders and magnitude of responses between groups. In addition, anti-S IgG levels directly correlated with a higher SARS-CoV-2 specific T-cell response (rho = 0.43; p = 0.027 and rho = 0.45; p = 0.02 for IFN-γ+ and TNF-α+ production of CD8+ T-cells, respectively). Activated T-cell phenotype in HTR was associated with a lower humoral response to SARS-CoV-2 vaccine.

Conclusion

HTR had humoral response after vaccination, although they showed lower levels of specific anti-S antibodies compared to HC. There were no significant differences in the SARS-CoV2-specific cellular response between the two groups. Obtaining satisfactory data on this type of response could potentially challenge the current vaccine guideline recommendations.

COVID-19 disease among children and young adults enrolled in the North American Pediatric Renal Trials and Collaborative Studies registry

BACKGROUND

Coronavirus disease of 2019 (COVID-19) has disproportionately affected adults with kidney disease. Data regarding outcomes among children with kidney disease are limited. The North American Pediatric Renal Trials Collaborative Studies Registry (NAPRTCS) has followed children with chronic kidney disease (CKD) since 1987 at 87 participating centers. This study aimed to evaluate the impact of COVID-19 among participants enrolled in the three arms of the registry: CKD, dialysis, and transplant.

METHODS

This was a retrospective cohort study of COVID-19 among participants in the NAPRTCS CKD, dialysis, and transplant registries from 2020 to 2022. Where appropriate, t-tests, chi-square analyses, and univariate logistic regression were used to evaluate the data.

RESULTS

The cohort included 1505 NAPRTCS participants with recent data entry; 260 (17%) had documented COVID-19. Infections occurred in all three registry arms, namely, 10% (n = 29) in CKD, 11% (n = 67) in dialysis, and 26% (n = 164) in transplant. The majority of participants (75%) were symptomatic. Hospitalizations occurred in 17% (n = 5) of participants with CKD, 27% (n = 18) maintenance dialysis participants, and 26% (n = 43) of transplant participants. Fourteen percent (n = 4) of CKD participants and 10% (n = 17) of transplant participants developed acute kidney injury (AKI), and a total of eight participants (one CKD, seven transplant) required dialysis initiation. Among transplant participants with moderate to severe illness, 40-43% developed AKI and 29-40% required acute dialysis. There were no reported deaths.

CONCLUSIONS

COVID-19 was documented in 17% of active NAPRTCS participants. While there was no documented mortality, the majority of participants were symptomatic, and a quarter required hospitalization.

Clinical manifestations and outcomes of coronavirus disease 2019 among pediatric liver transplant recipients in the delta and omicron variant pandemic: A retrospective study

To determine the clinical manifestations and outcomes of the coronavirus disease 2019 (COVID-19) in children who underwent liver transplantation (LT). A retrospective study was conducted at a transplant center in Thailand to include LT recipients aged < 18 years who had been infected with COVID-19. Out of a total of 54 children, there were 31 probable cases (57.4%) diagnosed using an antigen test kit and 23 confirmed cases (42.6%) diagnosed using polymerase chain reaction (14 children) or severe acute respiratory syndrome coronavirus 2 antigen (9 children). Approximately half of the children (25, 46.3%) received the BNT162b2 vaccine before the infection, with 3 and 2 doses in 5 and 18 children, respectively. While some had COVID-19 during the delta pandemic, most (46 children, 85.2%) were infected during the omicron pandemic, of which manifestations included fever (67.4%), cough (50%), and rhinorrhea (47.8%), and symptoms lasted approximately 3 days. None had severe diseases. All patients with mild-to-moderate disease were advised to continue the same immunosuppressive therapy as before the infection. Compared to unvaccinated children or children with one dose of the vaccine, fever was less common in those who received ≥ 2 doses (OR: 0.08; 95%CI: 0.01-0.57, adjusted for age and immunosuppressive types). Favipiravir was prescribed in most patients (90.7%). Only a few children had long COVID-19 or abnormal liver function tests lasting > 1 month (4 children, 7.4%, both). Pediatric LT recipients with COVID-19 during the delta and omicron variant pandemic reported mild symptoms despite undergoing immunosuppressive therapy.

COVID-19 Disease in Pediatric Solid Organ Transplantation from Alpha to Omicron: A High Monocyte Count in the Preceding Three Months Portends a Risk for Severe Disease

IMPORTANCE

Planning for future resurgences in SARS-CoV-2 infection is necessary for providers who care for immunocompromised patients.

OBJECTIVE

to determine factors associated with COVID-19 disease severity in immunosuppressed children.

DESIGN

a case series of children with solid organ transplants diagnosed with SARS-CoV-2 infection between 15 March 2020 and 31 March 2023.

SETTING

a single pediatric transplant center.

PARTICIPANTS

all children with a composite transplant (liver, pancreas, intestine), isolated intestine transplant (IT), isolated liver transplant LT), or simultaneous liver kidney transplant (SLK) with a positive PCR for SARS-CoV-2.

EXPOSURE

SARS-CoV-2 infection.

MAIN OUTCOME AND MEASURES

We hypothesized that children on the most immunosuppression, defined by the number of immunosuppressive medications and usage of steroids, would have the most severe disease course and that differential white blood cell count in the months preceding infection would be associated with likelihood of having severe disease. The hypothesis being tested was formulated during data collection. The primary study outcome measurement was disease severity defined using WHO criteria.

RESULTS

77 children (50 LT, 24 intestine, 3 SLK) were infected with SARS-CoV-2, 57.4 months from transplant (IQR 19.7-87.2). 17% were ≤1 year post transplant at infection. 55% were male, 58% were symptomatic and ~29% had severe disease. A high absolute lymphocyte count at diagnosis decreased the odds of having severe COVID-19 disease (OR 0.29; CI 0.11-0.60; p = 0.004). Conversely, patients with a high absolute monocyte count in the three months preceding infection had increased odds of having severe disease (OR 30.49; CI 1.68-1027.77; p = 0.033). Steroid use, higher tacrolimus level, and number of immunosuppressive medications at infection did not increase the odds of having severe disease.

CONCLUSIONS AND RELEVANCE

The significance of a high monocyte count as predictor of severe disease potentially confirms the importance of monocytic inflammasome-driven inflammation in COVID-19 pathogenesis. Our data do not support reducing immunosuppression in the setting of infection. Our observations may have important ramifications in resource management as vaccine- and infection-induced immunity wanes.

Reduced Humoral and Cellular Immune Response to Primary COVID-19 mRNA Vaccination in Kidney Transplanted Children Aged 5-11 Years

The situation of limited data concerning the response to COVID-19 mRNA vaccinations in immunocom-promised children hinders evidence-based recommendations. This prospective observational study investigated humoral and T cell responses after primary BNT162b2 vaccination in secondary immunocompromised and healthy children aged 5-11 years. Participants were categorized as: children after kidney transplantation (KTx, n = 9), proteinuric glomerulonephritis (GN, n = 4) and healthy children (controls, n = 8). Expression of activation-induced markers and cytokine secretion were determined to quantify the T cell response from PBMCs stimulated with peptide pools covering the spike glycoprotein of SARS-CoV-2 Wuhan Hu-1 and Omicron BA.5. Antibodies against SARS-CoV-2 spike receptor-binding domain were quantified in serum. Seroconversion was detected in 56% of KTx patients and in 100% of the GN patients and controls. Titer levels were significantly higher in GN patients and controls than in KTx patients. In Ktx patients, the humoral response increased after a third immunization. No differences in the frequency of antigen-specific CD4+ and CD8+ T cells between all groups were observed. T cells showed a predominant anti-viral capacity in their secreted cytokines; however, this capacity was reduced in KTx patients. This study provides missing evidence concerning the humoral and T cell response in immunocompromised children after COVID-19 vaccination.

SARS-CoV-2 Infection, Inflammation, Immunonutrition, and Pathogenesis of COVID-19

The COVID-19 pandemic, caused by the coronavirus, SARS-CoV-2, has claimed millions of lives worldwide in the past two years. Fatalities among the elderly with underlying cardiovascular disease, lung disease, and diabetes have particularly been high. A bibliometrics analysis on author's keywords was carried out, and searched for possible links between various coronavirus studies over the past 50 years, and integrated them. We found keywords like immune system, immunity, nutrition, malnutrition, micronutrients, exercise, inflammation, and hyperinflammation were highly related to each other. Based on these findings, we hypothesized that the human immune system is a multilevel super complex system, which employs multiple strategies to contain microorganism infections and restore homeostasis. It was also found that the behavior of the immune system is not able to be described by a single immunological theory. However, one main strategy is "self-destroy and rebuild", which consists of a series of inflammatory responses: 1) active self-destruction of damaged/dysfunctional somatic cells; 2) removal of debris and cells; 3) rebuilding tissues. Thus, invading microorganisms' clearance could be only a passive bystander response to this destroy-rebuild process. Microbial infections could be self-limiting and promoted as an indispensable essential nutrition for the vast number of genes existing in the microorganisms. The transient nutrition surge resulting from the degradation of the self-destroyed cell debris coupled with the existing nutrition state in the patient may play an important role in the pathogenesis of COVID-19. Finally, a few possible coping strategies to mitigate COVID-19, including vaccination, are discussed.

The case against COVID-19 vaccine mandates in pediatric solid organ transplantation

BACKGROUND

The American Society of Transplantation in conjunction with the International Society for Heart and Lung Transplantation released a joint statement on August 13, 2021 in which they strongly recommend that solid organ transplant (SOT) recipients and their eligible household members and close contacts be vaccinated against SARS-CoV-2 with an approved COVID-19 vaccine. Some SOT programs have gone further and will refuse to list or transplant candidates unless the candidate and their household are vaccinated against SARS-CoV-2.

METHODS

Two general pediatrician-ethicists use current best evidence and moral theory to argue why it is unethical to mandate COVID-19 vaccination for pediatric SOT candidates, their primary support person, and their households.

RESULTS

Pediatric vaccine mandates are most justifiable when they prevent the harm of a serious vaccine preventable disease (VPD) in children in settings where transmission is highly likely and there are no alternatives that are effective in preventing transmission that intrude less on individual freedom. An additional justification for a vaccine mandate in the SOT context is stewardship of a scarce resource if there is significant risk of graft loss from the VPD to an unvaccinated SOT candidate or recipient. Current evidence does not support fulfillment of these criteria in pediatric solid organ transplantation.

CONCLUSIONS

Making SOT listing contingent on COVID-19 vaccination is problematic. Though there is some risk of harm to a pediatric SOT candidate in remaining unvaccinated, the risk of harm of not being listed and transplanted is greater and overriding.

Caregiver COVID-19 vaccination for solid organ transplant candidates

An increasing proportion of transplant centers have implemented a mandate for vaccination against COVID-19 for solid organ transplant candidates. There has been comparatively little exploration of the ethical considerations of mandating vaccination of a candidate's primary caregiver, despite a high risk of transmission given the close nature of contact between the candidate and caregiver. We examine how a caregiver mandate can improve overall utility in organ allocation, particularly in circumstances where vaccine effectiveness at preventing transmission and serious disease is low among recipients but high in caregivers. Our analysis reveals how sensitive such mandates must be to the evolving circumstances of disease severity, transmissibility, and vaccine effectiveness: as the facts change, the degree of benefit gained and therefore the degree of infringement on access to transplant and caregiver choice that is tolerated will likewise change.

Early Use of Sotrovimab in Children: A Case Report of an 11-Year-Old Kidney Transplant Recipient Infected with SARS-CoV-2

BACKGROUND

The use of virus-neutralizing monoclonal antibodies has been approved in fragile populations, including kidney transplant recipients, who are at risk of developing severe COVID-19. Sotrovimab is the only currently available anti-SARS-CoV-2 neutralizing monoclonal antibody with activity against the new Omicron variant of concern. While sotrovimab has been approved in adolescents and adults, studies regarding its efficacy and safety in children aged less than 12 years old and weighing less than 40 kg are still lacking. Here, we report a first case of a child, who was treated early with sotrovimab after a kidney transplant.

CASE REPORT

At the end of January 2022, a 11-year-old male child underwent a deceased-donor kidney transplant and became infected with SARS-CoV-2 during the first day after surgery. Due to the increased risk of developing severe COVID-19, based on the predominance of Omicron and the patient's renal function, the child was treated with sotrovimab. The clinical course was successful and no adverse reactions were reported.

CONCLUSIONS

For the first time, we report the well-tolerated use of sotrovimab in children under 12 years old. As the pandemic affects children across the globe, urgent data on sotrovimab dosing in children with a higher risk of developing severe COVID-19 are needed.

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.