Perspectives on COVID-19 vaccination among kidney and pancreas transplant recipients living in New York City

Risk factors for SARS-CoV-2 infection and severe COVID-19 in unvaccinated solid organ transplant recipients

The role of immunosuppressive therapy on SARS-CoV-2 infection risk and COVID-19 severity remains unclear in unvaccinated solid organ transplant recipients. We included 1957 organ transplant recipients between July 2020 and April 2021 to analyze whether baseline immunosuppressive therapy and other risk factors are associated with SARS-CoV-2 infection and severe COVID-19. In total, 247 (12.6%) had SARS-CoV-2 (defined as positive nasopharyngeal swab and/or positive antibody titer). Of these, 57 (23.1%) had severe COVID-19, defined as oxygen supplementation, intensive care unit admission or death. Multivariable analysis identified diabetes (hazard ratio (HR) 1.39 (95% confidence interval (CI) 1.05-1.83)), chronic lung disease (HR 1.71 (95% CI 1.13-2.60)) and contact with a COVID-19 positive individual (HR 3.61 (95% CI 2.61-4.99) as independent risk factors for SARS-CoV-2 infection. There was no association between immunosuppressive therapy and infection risk. Severe COVID-19 was multivariably associated with hypertension (OR 5.45 (95% CI 1.66-17.84)), chronic kidney disease (OR 3.55 (95% CI 1.75-7.19)), corticosteroid use (OR 2.93 (95% CI 1.03-2.55)) and having a COVID-19 positive housemate (OR 6.77 (95% CI 2.65-17.28)). In conclusion, baseline corticosteroid use, but no other immunosuppressive agent, is independently associated with severe COVID-19 in unvaccinated SOT recipients after correction for hypertension, chronic kidney disease, housemates affected by COVID-19 and transplant type.

Perceptions of COVID-19 Vaccination Among Organ Transplant Recipients

BACKGROUND

Understanding COVID-19 vaccine hesitancy in organ transplant recipients (OTRs) is critical given clear-albeit attenuated-benefits from vaccination.

METHODS

Adult OTRs were surveyed regarding sociodemographic data, medical history, and vaccine-related values. A novel outcome variable called the Vaccine Acceptance Composite Score (VACS) was built as the average Likert score of seven domains of vaccine confidence. To examine its association with several factors and individual adherence to COVID-19 vaccine recommendations, univariable odds ratios and relative operating characteristic areas under the curve (AUC) values were calculated.

RESULTS

Of 46 OTRs included, 32.6% identified as female, 13.3% as Black, and 6.77% as Hispanic or Latino/a/x. The median age was 58 years old. 93.5% of patients were kidney transplant recipients, and 63.0% previously had COVID-19. Patients were most concerned about COVID-19 vaccine-associated risks (46.3%), its potential effect on allograft (47.6%), and motives of government officials involved with vaccine policy (55.6%). Politically conservative patients were likelier to have lower VACS, whereas those who lived with someone ≥65 years old were likelier to have higher VACS. The VACS was not significantly associated with race, income, religious beliefs, comorbidities, COVID-19 history, or influenza vaccination status. Higher VACS was associated with ≥3 and ≥4 COVID-19 immunizations.

CONCLUSIONS

This study highlighted political beliefs and elderly household members as correlates of vaccine acceptance among OTRs. The VACS may be a useful tool to help standardize multifaceted analyses in vaccination-focused behavioral research. In clinical practice, it could help identify individuals and groups at risk for vaccine hesitancy, who may benefit from tailored outreach and educational interventions.

Reasons for COVID-19 Vaccine Hesitancy Among Patients Listed for Solid Organ Transplants

BACKGROUND

Patients listed for solid organ transplants (LSOTP) are at high risk for severe COVID-19 outcomes. Despite national guidelines recommending COVID-19 vaccination for LSOTP, vaccine hesitancy and underuse are reported in this population; however, reasons for this finding have not been examined thoroughly.

METHODS

This single-center retrospective survey analysis aimed to characterize reasons for COVID-19 vaccine hesitancy among 110 heart, liver, and kidney patients LSOTP who had not received all the recommended vaccine doses at the time of the study. Survey questions also investigated experiences with influenza vaccination.

RESULTS

Fifty-four patients (49.1%) responded to the telephone survey. The most common reasons for vaccine hesitancy were perceived lack of research in vaccine development (31%), fear of vaccine-related side effects (22%), and belief that the vaccine was unnecessary (20%). Of the respondents, 35% reported changing their vaccine perception after being listed for a transplant, most commonly attributing this to a perception that the COVID-19 vaccine is not safe for transplant recipients (32%). Gender differences in hesitancy reasons were observed, with males more likely to delay vaccination until after transplantation, although this difference was not significant (P = .07). Despite these findings, 54% of all respondents reported receiving annual influenza vaccines consistently.

CONCLUSION

Despite their risk, patients LSOTP show significant hesitancy toward COVID-19 vaccines owing to perceived safety and necessity issues. The results of this study can inform targeted educational efforts to address and rectify misconceptions and concerns about COVID-19 vaccination among patients LSOTP. Future studies focused on larger, more diverse cohorts are needed to expand our understanding of and address vaccination hesitancy among this vulnerable patient population.

Covid-19 Vaccine Hesitancy and Under-Vaccination among Marginalized Populations in the United States and Canada: A Scoping Review

BACKGROUND

Amid persistent disparities in Covid-19 vaccination and burgeoning research on vaccine hesitancy (VH), we conducted a scoping review to identify multilevel determinants of Covid-19 VH and under-vaccination among marginalized populations in the U.S. and Canada.

METHODS

Using the scoping review methodology developed by the Joanna Briggs Institute, we designed a search string and explored 7 databases to identify peer-reviewed articles published from January 1, 2020-October 25, 2022. We combine frequency analysis and narrative synthesis to describe factors influencing Covid-19 VH and under-vaccination among marginalized populations.

RESULTS

The search captured 11,374 non-duplicated records, scoped to 103 peer-reviewed articles. Among 14 marginalized populations identified, African American/Black, Latinx, LGBTQ+, American Indian/Indigenous, people with disabilities, and justice-involved people were the predominant focus. Thirty-two factors emerged as influencing Covid-19 VH, with structural racism/stigma and institutional mistrust (structural)(n = 71) most prevalent, followed by vaccine safety (vaccine-specific)(n = 62), side effects (vaccine-specific)(n = 50), trust in individual healthcare provider (social/community)(n = 38), and perceived risk of infection (individual)(n = 33). Structural factors predominated across populations, including structural racism/stigma and institutional mistrust, barriers to Covid-19 vaccine access due to limited supply/availability, distance/lack of transportation, no/low paid sick days, low internet/digital technology access, and lack of culturally- and linguistically-appropriate information.

DISCUSSION

We identified multilevel and complex drivers of Covid-19 under-vaccination among marginalized populations. Distinguishing vaccine-specific, individual, and social/community factors that may fuel decisional ambivalence, more appropriately defined as VH, from structural racism/structural stigma and systemic/institutional barriers to vaccination access may better support evidence-informed interventions to promote equity in access to vaccines and informed decision-making among marginalized populations.

The Impact of the COVID-19 Pandemic on Patients With CKD: Systematic Review of Qualitative Studies

RATIONALE & OBJECTIVE

COVID-19 disproportionately affects people with comorbidities, including chronic kidney disease (CKD). We describe the impact of COVID-19 on people with CKD and their caregivers.

STUDY DESIGN

A systematic review of qualitative studies.

SETTING & STUDY POPULATIONS

Primary studies that reported the experiences and perspectives of adults with CKD and/or caregivers were eligible.

SEARCH STRATEGY & SOURCES

MEDLINE, Embase, PsycINFO, CINAHL searched from database inception to October 2022.

DATA EXTRACTION

Two authors independently screened the search results. Full texts of potentially relevant studies were assessed for eligibility. Any discrepancies were resolved by discussion with another author.

ANALYTICAL APPROACH

A thematic synthesis was used to analyze the data.

RESULTS

Thirty-four studies involving 1,962 participants were included. Four themes were identified: exacerbating vulnerability and distress (looming threat of COVID-19 infection, intensifying isolation, aggravating pressure on families); uncertainty in accessing health care (overwhelmed by disruption of care, confused by lack of reliable information, challenged by adapting to telehealth, skeptical about vaccine efficacy and safety); coping with self-management (waning fitness due to decreasing physical activity, diminishing ability to manage diet, difficulty managing fluid restrictions, minimized burden with telehealth, motivating confidence and autonomy); and strengthening sense of safety and support (protection from lockdown restrictions, increasing trust in care, strengthened family connection).

LIMITATIONS

Non-English studies were excluded, and inability to delineate themes based on stage of kidney and treatment modality.

CONCLUSIONS

Uncertainty in accessing health care during the COVID-19 pandemic exacerbated vulnerability, emotional distress, and burden, and led to reduced capacity to self-manage among patients with CKD and their caregivers. Optimizing telehealth and access to educational and psychosocial support may improve self-management and the quality and effectiveness of care during a pandemic, mitigating potentially catastrophic consequences for people with CKD.

PLAIN-LANGUAGE SUMMARY

During the COVID-19 pandemic, patients with chronic kidney disease (CKD) faced barriers and challenges to accessing care and were at an increased risk of worsened health outcomes. To understand the perspectives about the impact of COVID-19 among patients with CKD and their caregivers, we conducted a systematic review of 34 studies involving 1,962 participants. Our findings demonstrated that uncertainty in accessing care during the COVID-19 pandemic exacerbated the vulnerability, distress, and burden of patients and impaired their abilities for self-management. Optimizing the use of telehealth and providing education and psychosocial services may mitigate the potential consequences for people with CKD during a pandemic.

Understanding Concerns about COVID-19 and Vaccination: Perspectives from Kidney Transplant Recipients

The COVID-19 pandemic poses a significant risk for immunosuppressed groups such as transplant patients. The purpose of this study was to improve our understanding of the impact of the COVID-19 pandemic on kidney transplant recipients, including their views on COVID-19 vaccination. Semi-structured interviews were conducted from December 2021 to August 2022 with 38 kidney transplant recipients who had an appointment with their transplant care team within the previous 6 months. We used qualitative thematic analysis to characterize the perspectives of interviewees. Regardless of COVID-19 vaccination status, most interviewees reported utilizing public health measures such as masking, hand washing, and avoiding crowds to protect themselves against COVID-19. Vaccinated interviewees (n = 31) noted that they chose to receive a COVID-19 vaccine because of their increased risk due to their immunocompromised state. For unvaccinated interviewees (n = 7), reasons for not receiving a COVID-19 vaccine included concerns about the safety and efficacy of the vaccine. Both vaccinated and unvaccinated interviewees expressed concerns about the lack of adequate testing of the vaccine in transplant patients and questioned if the vaccine might have unknown side effects for transplant recipients. Regardless of the vaccination status, most interviewees noted having trust in their healthcare team. Interviewees also described interpersonal tensions that arose during the pandemic, many of which surrounded vaccination and other preventive measures that were important to participants to protect their health. Together, these data demonstrate differing concerns and experiences related to the COVID-19 pandemic for vaccinated and unvaccinated transplant recipients. These findings highlight the unique needs of transplant recipients and reveal opportunities to support this vulnerable patient population in efforts to protect their health as the COVID-19 pandemic evolves.

Attitudes of patients with renal disease on xenotransplantation: A systematic review

BACKGROUND

Recent years have seen major advancements in xenotransplantation: the first pig-to-human heart transplant, the development of a brain-dead recipient model for kidney xenotransplantation, and the registration of the first xenokidney clinical trial. The attitudes of patients with kidney disease or transplants on xenotransplantation and an assessment of their reservations and considerations regarding the technology are crucial to successful clinical translation and eventual widespread implementation.

METHODS

This systematic review was registered through PROSPERO (CRD42022344581) prior to initiation of the study and reported using the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines. We included studies that evaluated attitudes towards and willingness to undergo xenotransplantation in patients with end-stage renal disease (ESRD), including those who had already undergone transplantation. MEDLINE (via Ovid), Embase (via Elsevier), and Web of Science (via Clarivate) were searched from database inception to July 15, 2022 by an experienced medical librarian for studies on xenotransplantation and attitudes. Abstracts and full text were screened using Covidence software and data items regarding study methodology, patient demographics, and attitudes regarding xenotransplantation were extracted using Microsoft Excel. Risk of bias assessments were performed using the Critical Appraisal Skills Programmed and National Institute of Health study quality assessment tools.

RESULTS

Of 1992 studies identified, 14 studies met the inclusion criteria. These studies were conducted across eight countries, four in the United States, for a total of 3114 patients on the kidney waitlist or with a kidney transplant. All patients were over 17 years old and 58% were male. Acceptance of a xenotransplant was assessed using surveys in 12 studies. Sixty-three percent (n = 1354) of kidney patients reported that they would accept a xenotransplant with function comparable to that of an allotransplant. Acceptance of xenografts with inferior function to allografts (15%) or as bridge organs (35%) to allotransplantation was lower. Specific concerns expressed by patients included graft function, infection, social stigma, and animal rights. Subgroup analyses showed higher acceptance in already transplanted compared to waitlist patients and white compared to Black Americans.

CONCLUSION

An understanding of patient attitudes and reservations is key to the successful execution of the first xenotransplantation clinical trials. This study compiles important factors to consider, such as patient concerns, attitudes regarding practical clinical scenarios for the use of xenotransplantation, and the impact of demographic factors on acceptance of this emerging technology.

Factors associated with COVID-19 vaccine uptake in people with kidney disease: an OpenSAFELY cohort study

OBJECTIVE

To characterise factors associated with COVID-19 vaccine uptake among people with kidney disease in England.

DESIGN

Retrospective cohort study using the OpenSAFELY-TPP platform, performed with the approval of NHS England.

SETTING

Individual-level routine clinical data from 24 million people across GPs in England using TPP software. Primary care data were linked directly with COVID-19 vaccine records up to 31 August 2022 and with renal replacement therapy (RRT) status via the UK Renal Registry (UKRR).

PARTICIPANTS

A cohort of adults with stage 3-5 chronic kidney disease (CKD) or receiving RRT at the start of the COVID-19 vaccine roll-out was identified based on evidence of reduced estimated glomerular filtration rate (eGFR) or inclusion in the UKRR.

MAIN OUTCOME MEASURES

Dose-specific vaccine coverage over time was determined from 1 December 2020 to 31 August 2022. Individual-level factors associated with receipt of a 3-dose or 4-dose vaccine series were explored via Cox proportional hazards models.

RESULTS

992 205 people with stage 3-5 CKD or receiving RRT were included. Cumulative vaccine coverage as of 31 August 2022 was 97.5%, 97.0% and 93.9% for doses 1, 2 and 3, respectively, and 81.9% for dose 4 among individuals with one or more indications for eligibility. Delayed 3-dose vaccine uptake was associated with younger age, minority ethnicity, social deprivation and severe mental illness-associations that were consistent across CKD severity subgroups, dialysis patients and kidney transplant recipients. Similar associations were observed for 4-dose uptake.

CONCLUSION

Although high primary vaccine and booster dose coverage has been achieved among people with kidney disease in England, key disparities in vaccine uptake remain across clinical and demographic groups and 4-dose coverage is suboptimal. Targeted interventions are needed to identify barriers to vaccine uptake among under-vaccinated subgroups identified in the present study.

Hesitancy toward the Full COVID-19 Vaccination among Kidney, Liver and Lung Transplant Recipients in Italy

BACKGROUND

Coronavirus disease 2019 (COVID-19) vaccination hesitancy is a threat as COVID-19 vaccines have reduced both viral transmission and virus-associated mortality rates, particularly in high-risk subgroups. Solid organ transplant recipients (SOTRs) are particularly vulnerable, as the underlying causes of their organ failure and the chronic immunosuppression are associated with a lower immune response to COVID-19 vaccines, and with an excessive risk of death due to SARS-CoV-2 infection. We aimed to evaluate COVID-19 vaccination hesitancy and its reasons in a population of SOTRs.

METHODS

All the SOTRs attending our post-transplant clinics were asked to fill in a vaccination status form with specific validated questions related to their willingness to receive a third vaccine dose. In the case of negative answers, the patients were encouraged to explain the reasons for their refusal. Among the SOTRs (1899), 1019 were investigated (53.7%).

RESULTS

Overall, 5.01% (51/1019) of the SOTRs raised concerns regarding the future third dose vaccination. In more detail, hesitancy rates were 3.3% (15/453), 4.2% (7/166), and 7.3% (29/400) among the investigated liver, lung, and kidney transplant recipients, respectively (p = 0.0018). The main reasons for hesitancy were fear of adverse events (30/51, 58.8%) and perceived lack of efficacy (21/51, 41.2%).

CONCLUSIONS

Full adherence to ongoing or future vaccination campaigns is crucial to prevent, or at least reduce, COVID-19-related morbidity and mortality in fragile patients. The identification of the reasons influencing COVID-19 vaccination hesitancy in these patients is very important to establish appropriate and targeted patient-doctor communication strategies, and to further implement specific vaccination campaigns.

Solid Organ Rejection following SARS-CoV-2 Vaccination or COVID-19 Infection: A Systematic Review and Meta-Analysis

Background: Solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection is extremely rare but can occur. T-cell recognition of antigen is the primary and central event that leads to the cascade of events that result in rejection of a transplanted organ. Objectives: To describe the results of a systematic review for solid organ rejections following SARS-CoV-2 vaccination or COVID-19 infection. Methods: For this systematic review and meta-analysis, we searched Proquest, Medline, Embase, Pubmed, CINAHL, Wiley online library, Scopus and Nature through the Preferred Reporting Items for Systematic Reviews and Meta Analyses (PRISMA) guidelines for studies on the incidence of solid organ rejection post-SARS-CoV-2 vaccination or COVID-19 infection, published from 1 December 2019 to 31 May 2022, with English language restriction. Results: One hundred thirty-six cases from fifty-two articles were included in the qualitative synthesis of this systematic review (56 solid organs rejected post-SARS-CoV-2 vaccination and 40 solid organs rejected following COVID-19 infection). Cornea rejection (44 cases) was the most frequent organ observed post-SARS-CoV-2 vaccination and following COVID-19 infection, followed by kidney rejection (36 cases), liver rejection (12 cases), lung rejection (2 cases), heart rejection (1 case) and pancreas rejection (1 case). The median or mean patient age ranged from 23 to 94 years across the studies. The majority of the patients were male (n = 51, 53.1%) and were of White (Caucasian) (n = 51, 53.7%) and Hispanic (n = 15, 15.8%) ethnicity. A total of fifty-six solid organ rejections were reported post-SARS-CoV-2 vaccination [Pfizer-BioNTech (n = 31), Moderna (n = 14), Oxford Uni-AstraZeneca (n = 10) and Sinovac-CoronaVac (n = 1)]. The median time from SARS-CoV-2 vaccination to organ rejection was 13.5 h (IQR, 3.2–17.2), while the median time from COVID-19 infection to organ rejection was 14 h (IQR, 5–21). Most patients were easily treated without any serious complications, recovered and did not require long-term allograft rejection therapy [graft success (n = 70, 85.4%), graft failure (n = 12, 14.6%), survived (n = 90, 95.7%) and died (n = 4, 4.3%)]. Conclusion: The reported evidence of solid organ rejections post-SARS-CoV-2 vaccination or COIVD-19 infection should not discourage vaccination against this worldwide pandemic. The number of reported cases is relatively small in relation to the hundreds of millions of vaccinations that have occurred, and the protective benefits offered by SARS-CoV-2 vaccination far outweigh the risks.

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.

COVID-19 Vaccines in Pancreatic Transplant Recipients: A Single-Center Observative Study

The SARS-CoV-2 pandemic was a real test of doctors' abilities to adapt and respond to patients' needs. The course of infection varied from influenza-like symptoms to severe infections with multi-organ failure and death. Therefore, the possibility of vaccination against the COVID-19 virus brought great hope. Since 2004, 240 pancreas and pancreas with kidney (simultaneous pancreas and kidney transplantation, pancreas after kidney, pancreas transplants alone) transplants were performed in our center. Currently, 130 transplant patients are under the care of the transplant clinic. All patients were informed about the possibility of vaccination against SARS-CoV-2 with the mRNA vaccine. The aim of the study was to evaluate the development of antibodies to SARS-CoV-2 in patients who had previously undergone transplantation. Fifty-three patients were vaccinated with the full double dose and 37 patients received an additional third dose. The level of antibodies in the IgM and IgG classes was assessed in patients' serum. The level of antibodies was assessed before administration of the vaccine and then after administration of the first and second doses. Most patients had no response to vaccination after 1 dose of the vaccine and 21 patients achieved therapeutic antibody levels after the full dose of vaccination. However, the highest titer of immunoglobulins was found in recipients who received the third dose. The use of vaccinations is safe and can protect the group of patients after pancreas transplantation from serious complications of SARS-CoV-2 infection despite the use of immunosuppressive drugs.

Return to School and COVID-19 Vaccination for Pediatric Solid Organ Transplant Recipients in the United States: Expert Opinion for 2021-2022

The COVID-19 pandemic continues to generate challenges for pediatric solid organ transplant (SOT) recipients and their families. As rates of COVID-19 fluctuate, new SARS-CoV-2 variants emerge, and adherence to and implementation of mitigation strategies vary from community to community, questions remain about the best and safest practices to prevent COVID-19 in vulnerable patients. Notably, decisions about returning to school remain difficult. We assembled a team of specialists in pediatric infectious diseases, transplant infectious diseases, public health, transplant psychology, and infection prevention and control to re-address concerns about school re-entry, as well as COVID-19 vaccines, for pediatric SOT recipients in the United States in 2021. Based on available literature and guidance from national organizations, we generated expert statements specific to pediatric SOT recipients focused on school attendance in 2021.

Systematic Review and Meta-Analysis of COVID-19 Vaccination Acceptance

INTRODUCTION

Vaccination is an essential intervention to curb the coronavirus disease 2019 (COVID-19) pandemic. This review aimed to estimate the pooled proportion of COVID-19 vaccine acceptance worldwide.

METHODS

A systematic search of the MEDLINE (PubMed) database using "COVID-19," "vaccine" and "acceptance" to obtain original research articles published between 2020 and July 2021. Only studies with full text and that were published in English were included. The Joanna Briggs Institute meta-analysis was used to assess the data quality. The meta-analysis was performed using generic inverse variance with a random-effects model using the Review Manager software.

RESULTS

A total of 172 studies across 50 countries worldwide were included. Subgroup analyses were performed with regard to vaccine acceptance, regions, population, gender, vaccine effectiveness, and survey time. The pooled proportion of COVID-19 vaccine acceptance was 61% (95% CI: 59, 64). It was higher in Southeast Asia, among healthcare workers, in males, for vaccines with 95% effectiveness, and during the first survey.

CONCLUSION

COVID-19 vaccine acceptance needs to be increased to achieve herd immunity to protect the population from the disease. It is crucial to enhance public awareness of COVID-19 vaccination and improve access to vaccines.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO 2021, identifier CRD42021268645.

Immunologic response of mRNA SARS-CoV-2 vaccination in adolescent kidney transplant recipients

BACKGROUND

In the general population, mRNA SARS-CoV-2 vaccines are highly efficacious. Early reports suggest a diminished antibody response in immunosuppressed adult solid organ transplant (SOT) patients, but this has not been reported in pediatrics.

METHODS

Adolescent kidney transplant recipients (KTR) at our center who received both doses of an mRNA SARS-CoV-2 vaccine had SARS-CoV-2 spike (S) protein antibody presence evaluated 4-8 weeks after their second dose of the vaccine as part of routine clinical care.

RESULTS

Thirteen of 25 fully vaccinated patients (52%) had a positive spike antibody. Median age of participants was 19 years old (IQR 18-20) and the median time from transplant was 5 years (IQR 4-9 years). KTR were treated with an immunosuppression regimen including a calcineurin inhibitor, corticosteroid, and antimetabolite (9 with mycophenolate, 3 with azathioprine, and 1 without an antimetabolite due to viremia). Of those who had an antibody response, fewer had a mycophenolate-containing immunosuppressant regimen than non-responders. There was a trend toward better vaccine response and higher anti-S antibody titers at lower doses of mycophenolate. Three patients with prior COVID-19 infection all had a positive antibody response.

CONCLUSION

Our results suggest vaccine response in adolescent KRT is lower than that of the general population, but similar to that previously described in adult SOT patients and slightly better than that seen in adult KTR. This data demonstrates vaccination is safe and supports immunizing KTR who remain hesitant. Future studies should focus on better understanding of the cellular immune response to vaccination and strategies to enhance vaccine immunogenicity in pediatric SOT patients.

Cellular immunity predominates over humoral immunity after homologous and heterologous mRNA and vector-based COVID-19 vaccine regimens in solid organ transplant recipients

Knowledge on the immunogenicity of vector-based and mRNA-vaccines in solid organ transplant recipients is limited. Therefore, SARS-CoV-2-specific T cells and antibodies were analyzed in 40 transplant recipients and 70 controls after homologous or heterologous vaccine-regimens. Plasmablasts and SARS-CoV-2-specific CD4 and CD8 T cells were quantified using flow cytometry. Specific antibodies were analyzed by ELISA and neutralization assay. The two vaccine types differed after the first vaccination, as IgG and neutralizing activity were more pronounced after mRNA priming (p = .0001 each), whereas CD4 and CD8 T cell levels were higher after vector priming (p = .009; p = .0001). All regimens were well tolerated, and SARS-CoV-2-specific antibodies and/or T cells after second vaccination were induced in 100% of controls and 70.6% of transplant recipients. Although antibody and T cell levels were lower in patients, heterologous vaccination led to the most pronounced induction of antibodies and CD4 T cells. Plasmablast numbers were significantly higher in controls and correlated with SARS-CoV-2-specific IgG- and T cell levels. While antibodies were only detected in 35.3% of patients, cellular immunity was more frequently found (64.7%) indicating that assessment of antibodies is insufficient to identify COVID-19-vaccine responders. In conclusion, heterologous vaccination seems promising in transplant recipients, and combined analysis of humoral and cellular immunity improves the identification of responders among immunocompromised individuals.

COVID-19 Vaccine Hesitancy in the United States: A Systematic Review

Vaccine hesitancy in the US throughout the pandemic has revealed inconsistent results. This systematic review has compared COVID-19 vaccine uptake across US and investigated predictors of vaccine hesitancy and acceptance across different groups. A search of PUBMED database was conducted till 17th July, 2021. Articles that met the inclusion criteria were screened and 65 studies were selected for a quantitative analysis. The overall vaccine acceptance rate ranged from 12 to 91.4%, the willingness of studies using the 10-point scale ranged from 3.58 to 5.12. Increased unwillingness toward COVID-19 vaccine and Black/African Americans were found to be correlated. Sex, race, age, education level, and income status were identified as determining factors of having a low or high COVID-19 vaccine uptake. A change in vaccine acceptance in the US population was observed in two studies, an increase of 10.8 and 7.4%, respectively, between 2020 and 2021. Our results confirm that hesitancy exists in the US population, highest in Black/African Americans, pregnant or breastfeeding women, and low in the male sex. It is imperative for regulatory bodies to acknowledge these statistics and consequently, exert efforts to mitigate the burden of unvaccinated individuals and revise vaccine delivery plans, according to different vulnerable subgroups, across the country.

Kidney transplant recipients' attitudes toward COVID-19 vaccination and barriers and enablers to vaccine acceptance

OBJECTIVE

To identify barriers and enablers to COVID-19 vaccination in renal transplant recipients who are undecided about vaccination.

METHODS

An online survey was distributed to 876 adult kidney transplant recipients at a tertiary referral service, who had not been vaccinated against COVID-19. The survey assessed willingness to be vaccinated, attitudes toward COVID-19 vaccines, and barriers and enablers to proceeding with vaccination.

RESULTS

The survey response rate was 54% (473/876). Three hundred and forty-six (73.1%) participants planned to receive vaccination (yes group), 105 (22.2%) were undecided, and 22 (4.7%) refused vaccination. The undecided group were younger but were not different in other demographic characteristics to the yes group. The undecided group were less positive toward (34.29% vs. 91.3%, p < .001) and more concerned about (93.3% vs. 25.1%, p < .001) vaccination than the yes group. Their concerns related to vaccine safety (including harm to their transplant), poor efficacy, and a lack of rigorous testing in transplant recipients. Undecided recipients had received less vaccine-specific information from medical specialists than the yes group. Most undecided participants (95.1%) were willing to proceed with vaccination with appropriate supports. The most desired supports were information and a recommendation to proceed with vaccination from their treating transplant specialist and team.

CONCLUSION(S)

Concerns about vaccine safety (including harm to transplant), poor vaccine efficacy, and lack of rigorous testing were barriers to vaccine uptake. Most undecided recipients would proceed with vaccination with specific recommendations and vaccine information provided by their transplant specialist/team. These simple interventions can be readily implemented to optimize vaccine uptake.

mTOR-Inhibition and COVID-19 in Kidney Transplant Recipients: Focus on Pulmonary Fibrosis

Kidney transplant recipients are at high risk of developing severe COVID-19 due to the coexistence of several transplant-related comorbidities (e.g., cardiovascular disease, diabetes) and chronic immunosuppression. As a consequence, a large part of SARS-CoV-2 infected patients have been managed with a reduction of immunosuppression. The mTOR-I, together with antimetabolites, have been often discontinued in order to minimize the risk of pulmonary toxicity and to antagonize pharmacological interaction with antiviral/anti-inflammatory drugs. However, at our opinion, this therapeutic strategy, although justified in kidney transplant recipients with severe COVID-19, should be carefully evaluated in asymptomatic/paucisymptomatic patients in order to avoid the onset of acute allograft rejections, to potentially exploit the mTOR-I antiviral properties, to reduce proliferation of conventional T lymphocytes (which could mitigate the cytokine storm) and to preserve Treg growth/activity which could reduce the risk of progression to severe disease. In this review, we discuss the current literature regarding the therapeutic potential of mTOR-Is in kidney transplant recipients with COVID-19 with a focus on pulmonary fibrosis.