COVID-19 vaccination immune paresis in heart and lung transplantation

International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024

The "International Society for Heart and Lung Transplantation Guidelines for the Evaluation and Care of Cardiac Transplant Candidates-2024" updates and replaces the "Listing Criteria for Heart Transplantation: International Society for Heart and Lung Transplantation Guidelines for the Care of Cardiac Transplant Candidates-2006" and the "2016 International Society for Heart Lung Transplantation Listing Criteria for Heart Transplantation: A 10-year Update." The document aims to provide tools to help integrate the numerous variables involved in evaluating patients for transplantation, emphasizing updating the collaborative treatment while waiting for a transplant. There have been significant practice-changing developments in the care of heart transplant recipients since the publication of the International Society for Heart and Lung Transplantation (ISHLT) guidelines in 2006 and the 10-year update in 2016. The changes pertain to 3 aspects of heart transplantation: (1) patient selection criteria, (2) care of selected patient populations, and (3) durable mechanical support. To address these issues, 3 task forces were assembled. Each task force was cochaired by a pediatric heart transplant physician with the specific mandate to highlight issues unique to the pediatric heart transplant population and ensure their adequate representation. This guideline was harmonized with other ISHLT guidelines published through November 2023. The 2024 ISHLT guidelines for the evaluation and care of cardiac transplant candidates provide recommendations based on contemporary scientific evidence and patient management flow diagrams. The American College of Cardiology and American Heart Association modular knowledge chunk format has been implemented, allowing guideline information to be grouped into discrete packages (or modules) of information on a disease-specific topic or management issue. Aiming to improve the quality of care for heart transplant candidates, the recommendations present an evidence-based approach.

Unlocking insights: Navigating COVID-19 challenges and Emulating future pandemic Resilience strategies with strengthening natural immunity

The original COVID-19 vaccines, developed against SARS-CoV-2, initially mitigated hospitalizations. Bivalent vaccine boosters were used widely during 2022-23, but the outbreaks persisted. Despite this, hospitalizations, mortality, and outbreaks involving dominant mutants like Alpha and Delta increased during winters when the population's vitamin D levels were at their lowest. Notably, 75 % of human immune cell/system functions, including post-vaccination adaptive immunity, rely on adequate circulatory vitamin D levels. Consequently, hypovitaminosis compromises innate and adaptive immune responses, heightening susceptibility to infections and complications. COVID-19 vaccines primarily target SARS-CoV-2 Spike proteins, thus offering only a limited protection through antibodies. mRNA vaccines, such as those for COVID-19, fail to generate secretory/mucosal immunity-like IgG responses, rendering them ineffective in halting viral spread. Additionally, mutations in the SARS-CoV-2 binding domain reduce immune recognition by vaccine-derived antibodies, leading to immune evasion by mutant viruses like Omicron variants. Meanwhile, the repeated administration of bivalent boosters intended to enhance efficacy resulted in the immunoparesis of recipients. As a result, relying solely on vaccines for outbreak prevention, it became less effective. Dominant variants exhibit increased affinity to angiotensin-converting enzyme receptor-2, enhancing infectivity but reducing virulence. Meanwhile, spike protein-related viral mutations do not impact the potency of widely available, repurposed early therapies, like vitamin D and ivermectin. With the re-emergence of COVID-19 and impending coronaviral pandemics, regulators and health organizations should proactively consider approval and strategic use of cost-effective adjunct therapies mentioned above to counter the loss of vaccine efficacy against emerging variants and novel coronaviruses and eliminate vaccine- and anti-viral agents-related serious adverse effects. Timely implementation of these strategies could reduce morbidity, mortality, and healthcare costs and provide a rational approach to address future epidemics and pandemics. This perspective critically reviews relevant literature, providing insights, justifications, and viewpoints into how the scientific community and health authorities can leverage this knowledge cost-effectively.

Comparative Analysis of Coronavirus disease 2019 Vaccine Efficacy in Heart Transplant Recipients on Standardized Immunotherapy Regimens

Objective

To assess the effect of coronavirus disease 2019 (COVID-19) infection on heart transplant recipients requiring immunotherapy. To investigate the effectiveness of vaccination in immunosuppressed heart transplant recipients during the initial years of the COVID-19 pandemic, and to examine the timing of COVID-19 infections in heart transplant recipients' posttransplantation.

Patients and Methods

International data on COVID-19 infection in immunosuppressed populations is limited. Heart transplant recipients requiring immunotherapy are at risk for increased complications with COVID-19 infection. The availability of vaccination and temporal trends in this population has not been well described. We report outcomes in immunosuppressed patients during the initial years of the COVID-19 pandemic from March 1, 2019, to October 31, 2021, at Mayo Clinic in Florida.

Results

A total of 98 patients were reviewed, of which 49 were COVID-19-positive (CP), and 49 were negative (CN). The cohort was well matched, with a median age of 58 years (49-65 years) in both groups. Females consisted of 41% in the CP group and 18.4% in the CN group. Immunosuppression was not significantly different for CP or CN patients. The median time from transplant to CP was 384 days (237-677 days). The CN group's median follow-up after transplant was 947 days (737-1191 days). The CP hospitalization rate was 24% with only 1 death. More CP patients were vaccinated than the CN group (92% vs 78%, P=.025).

Conclusion

Our study sheds light on COVID-19's effect on heart transplant recipients and vaccination in this population. Our findings suggest a potentially heightened infection risk within the first 1.5 years posttransplant, highlighting the need to optimize management strategies and vaccine efficacy in this vulnerable group.

Measures to Increase Immunogenicity of SARS-CoV-2 Vaccines in Solid Organ Transplant Recipients: A Narrative Review

Purpose of review: To review the data on the immunogenicity of COVID-19 vaccines, administered by different strategies, in solid organ transplant recipients (SOTRs). Recent findings: COVID-19 booster vaccines were given to SOTRs as a widespread practice in many transplant centers, mostly as the third and/or fourth dose in an extended vaccine series, with a significantly improved humoral response compared with the initial two-dose scheme. However, one-third of SOTRs remained unresponsive, despite these boosters. Next steps: Vaccination with standard dosing remains the most feasible strategy for attaining protection against COVID-19. Additional booster doses and temporarily holding or reducing mycophenolate mofetil/mycophenolic acid may provide immunogenicity to vaccines, according to recent studies demonstrating some efficacy with these measures. Preexposure prophylaxis with monoclonal antibodies showed benefit in immunocompromised patients but is no longer recommended by the National Institutes of Health (NIH) due to diminished efficacy against Omicron and recent variants. Screening for the presence and titers of SARS-CoV-2-specific antibodies in SOTRs is not recommended in most clinical settings. T cell-based techniques are needed to evaluate vaccine efficacy and risk of infection. As SARS-CoV-2 continues to evolve, new vaccines based on conservative protein component/complexes of the COVID virus, in addition to its spike protein, are warranted to offer prolonged protection.

Third dose of the BNT162b2 vaccine in cardiothoracic transplant recipients: predictive factors for humoral response

BACKGROUND

We report the results of a prospective study on the immunogenicity of a 3rd dose of BNT162b2 in thoracic organ recipients with no or minimal response following a two-dose BNT162b2 vaccination scheme.

METHODS

A total of 243 transplant recipients received a homologue 3rd dose. Anti-SARS-CoV2-immunoglobulins (IgGs) were monitored immediately before (T1), 4 weeks (T2) as well as 2 and 4 months after the 3rd dose. Neutralizing antibody capacity (NAC) was determined at T2. To reveal predictors for detectable humoral response, patients were divided into a positive response group (n = 129) based on the combined criteria of IgGs and NAC above the defined cut-offs at T2-and a group with negative response (n = 114), with both, IgGs and NAC beyond the cut-offs.

RESULTS

The 3rd dose induced a positive humoral response in 53% of patients at T2, 47% were still non-responsive. Sero-positivity was significantly stronger in patients who presented with weak, but detectable IgGs already prior to the booster (T1), when compared to those with no detectable response at T1. Multivariable analysis identified age > 55 years, a period since transplantation < 2 years, a reduced glomerular filtration rate, a triple immunosuppressive regimen, and the use of tacrolimus and of mycophenolate as independent risk factors for lack of humoral response.

CONCLUSIONS

Our data indicate that a lack of immunogenicity is linked to the type and extent of maintenance immunosuppression. The necessity of the cumulative immunosuppressive regimen might individually be questioned and possibly be reduced to enhance the chance of an immune response following an additional booster dose.

COVID-19 Prevention in Solid Organ Transplant Recipients: Current State of the Evidence

Although COVID-19 vaccines are safe, most organ transplant recipients fail to mount an antibody response after two mRNA vaccines. Thus, three mRNA vaccines constitute a primary vaccine series after solid organ transplant. However, neutralizing antibodies after three or greater mRNA vaccines are lower against Omicron versus older variants. Predictors of attenuated responses include age, vaccination within 1 year from transplant, mycophenolate, and BNT162b2. Some seronegative transplant recipients exhibit durable T-cell responses. Vaccine effectiveness in transplants is lower than in the general population. Immunosuppression reduction around revaccination warrants further study. Monoclonal antibody pre-exposure prophylaxis may be protective against susceptible variants.

Controlling Chronic Diseases and Acute Infections with Vitamin D Sufficiency

Apart from developmental disabilities, the prevalence of chronic diseases increases with age especially in those with co-morbidities: vitamin D deficiency plays a major role in it. Whether vitamin D deficiency initiates and/or aggravates chronic diseases or vice versa is unclear. It adversely affects all body systems but can be eliminated using proper doses of vitamin D supplementation and/or safe daily sun exposure. Maintaining the population serum 25(OH)D concentration above 40 ng/mL (i.e., sufficiency) ensures a sound immune system, minimizing symptomatic diseases and reducing infections and the prevalence of chronic diseases. This is the most cost-effective way to keep a population healthy and reduce healthcare costs. Vitamin D facilitates physiological functions, overcoming pathologies such as chronic inflammation and oxidative stress and maintaining broader immune functions. These are vital to overcoming chronic diseases and infections. Therefore, in addition to following essential public health and nutritional guidance, maintaining vitamin D sufficiency should be an integral part of better health, preventing acute and chronic diseases and minimize their complications. Those with severe vitamin D deficiency have the highest burdens of co-morbidities and are more vulnerable to developing complications and untimely deaths. Vitamin D adequacy improves innate and adaptive immune systems. It controls excessive inflammation and oxidative stress, generates antimicrobial peptides, and neutralizes antibodies via immune cells. Consequently, vitamin D sufficiency reduces infections and associated complications and deaths. Maintaining vitamin D sufficiency reduces chronic disease burden, illnesses, hospitalizations, and all-cause mortality. Vulnerable communities, such as ethnic minorities living in temperate countries, older people, those with co-morbidities, routine night workers, and institutionalized persons, have the highest prevalence of vitamin D deficiency-they would significantly benefit from vitamin D and targeted micronutrient supplementation. At least now, health departments, authorities, and health insurance companies should start assessing, prioritizing, and encouraging this economical, non-prescription, safe micronutrient to prevent and treat acute and chronic diseases. This approach will significantly reduce morbidity, mortality, and healthcare costs and ensure healthy aging.

Coronavirus Disease 2019 and Heart Transplantation: Single-Center Experience and Review of the Literature

Coronavirus disease 2019 (COVID-19) was declared a global pandemic in March 2020, and since then it has had a significant impact on healthcare including on solid organ transplantation. Based on age, immunosuppression, and prevalence of chronic comorbidities, heart transplant recipients are at high risk of adverse outcomes associated with COVID-19. In our center, 31 heart transplant recipients were diagnosed with COVID-19 from March 2020 to September 2021. They required: hospitalization (39%), intensive care (10%), and mechanical ventilation (6%) with overall short-term mortality of 3%. Early outpatient use of anti-SARS CoV-2 monoclonal antibodies in our heart transplant recipients was associated with a reduction in the risk of hospitalization, need for intensive care, and death related to COVID-19. In prior multicenter studies, completed in different geographic areas and pandemic timeframes, diverse rates of hospitalization (38-91%), mechanical ventilation (4-38%), and death (16-33%) have been reported. Progression of disease and adverse outcomes were most significantly associated with severity of lymphopenia, chronic comorbid conditions like older age, chronic allograft vasculopathy, increased body mass index, as well as intensity of baseline immune suppression. In this article, we also review the current roles and limitations of vaccination, anti-viral agents, and anti-severe acute respiratory syndrome coronavirus 2 monoclonal antibodies in the management of heart transplant recipients. Our single-center experience, considered together with other studies indicates a trend toward improved outcomes among heart transplant patients with COVID-19.

Efficacy and safety of the SARS-CoV-2 mRNA vaccine in lung transplant recipients: a possible trigger of rejection

OBJECTIVE

Solid organ transplant recipients have an increased risk of developing severe coronavirus disease 2019 (COVID-19). Although SARS-CoV-2 mRNA vaccination has been strongly recommended for solid organ transplant recipients, its efficacy and safety have remained unknown.

METHODS

We performed an observational prospective cohort study in 18 lung transplant recipients who received two doses of SARS-CoV-2 mRNA vaccine, including BNT162b2 (n = 17) or mRNA-1273 (n = 1), between June and October 2021. The titers of IgG antibodies against the SARS-CoV-2 spike protein (S-IgG) were measured in serum samples collected before the prime dose, three weeks after the prime dose, and four weeks after the booster dose. Reactogenicity and adverse events were evaluated after vaccination.

RESULTS

There were no recipients with previous SARS-CoV-2 infection prior to vaccination. S-IgG levels were elevated in 2/18 (11.1%) recipients after the prime dose and in 5/18 recipients (27.8%) after the booster dose (31.7 ± 30.6 U/ml). The time from transplantation to vaccination tended to be longer in the seropositive group than the seronegative group [7.5 (3.9-10.2) vs 2.8 (1.9-4.0) years, p = 0.059]. Maintenance dose of mycophenolate mofetil tended to be lower in the seropositive group than in the seronegative group [500 (250-500) vs 1000 (1000-1000) mg/day, p = 0.088]. Regarding the adverse events after vaccination, the development of chronic lung allograft dysfunction (CLAD) or antibody-mediated rejection (AMR) were observed in two seropositive patients.

CONCLUSIONS

The antibody response to the SARS-CoV-2 mRNA vaccine was quite poor in lung transplant recipients. We experienced cases that developed clinical CLAD or AMR that was likely related to SARS-CoV-2 vaccination.

SARS-CoV-2 vaccine booster in solid organ transplant recipients previously immunised with inactivated versus mRNA vaccines: A prospective cohort study

Background

Solid-organ transplant (SOT) recipients have worse COVID-19 outcomes than general population and effective immunisation in these patients is essential but more difficult to reach. We aimed to determine the immunogenicity of an mRNA SARS-CoV-2 vaccine booster in SOT recipients previously immunised with either inactivated or homologous SARS-CoV-2 mRNA vaccine.

Methods

Prospective cohort study of SOT recipients under medical care at Red de Salud UC-CHRISTUS, Chile, previously vaccinated with either CoronaVac or BNT162b2. All participants received a BNT162b2 vaccine booster. The primary study end point was anti-SARS-CoV-2 total IgG antibodies (TAb) seropositivity at 8-12 weeks (56-84 days) post booster. Secondary end points included neutralising antibodies (NAb) and specific T-cell responses.

Findings

A total of 140 (50% kidney, 38% liver, 6% heart) SOT recipients (mean age 54 [13.6] years; 64 [46%] women) were included. Of them, 62 had homologous (three doses of BNT162b2) and 78 heterologous vaccine schedules (two doses of CoronaVac followed by BNT162b2 booster). Boosters were received at a median of 21.3 weeks after primary vaccination. The proportion achieving TAb seropositivity (82.3% vs 65.4%, P = 0.035) and NAb positivity (77.4% vs 55.1%, P = 0.007) were higher for the homologous versus the heterologous group. On the other hand, the number of IFN-γ and IL-2 secreting SARS-CoV-2-specific T-cells did not differ significantly between groups.

Interpretation

This cohort study shows that homologous mRNA vaccine priming plus boosting in SOT recipients, reaches a significantly higher humoral immune response than inactivated SARS-CoV-2 vaccine priming followed by heterologous mRNA booster.

Funding

School of Medicine, UC-Chile and ANID.ClinicalTrials.gov ID: NCT05124509.

Clinical course of SARS-CoV-2 infection and recovery in lung transplant recipients

BACKGROUND

Reports on outcomes following severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in lung transplant recipients remain limited.

METHODS

We performed a single-center, observational study of outcomes in lung transplant recipients diagnosed with SARS-CoV-2 between 5/1/2020 and 3/15/2022 that were followed for a median of 123 days. We analyzed changes in spirometry, acute lung allograft dysfunction (ALAD) incidence, hospitalization, mechanical ventilation needs, secondary infection, and survival.

RESULTS

In our cohort of 336 patients, 103 developed coronavirus disease (COVID) (27 pre-Delta, 20 Delta, and 56 Omicron-era). Twenty-five patients (24%) required hospitalization and 10 patients ultimately died (10%). Among 85 survivors who completed ambulatory spirometry, COVID-19 did not alter change in forced expiratory volume in 1 s (FEV1 ) or forced vital capacity (FVC) over time compared to the preceding 6 months. The pre-COVID FEV1 change was -0.05 ml/day (IQR -0.50 to 0.60) compared to -0.20 ml/day (IQR -1.40 to 0.70) post-COVID (p = .16). The pre-COVID change in FVC was 0.20 ml/day (IQR -0.60 to 0.70) compared to 0.05 ml/day (IQR -1.00 to 1.10) post-COVID (p = .76). Although the cohort overall had stable lung function, 33 patients (39%) developed ALAD or accelerated chronic lung allograft dysfunction (FEV1 decline >10% from pre-COVID baseline). Nine patients (35%) with ALAD recovered lung function. Within 3 months of acute COVID infection, 18 patients (17%) developed secondary infections, the majority being bacterial pneumonia. Finally, vaccination with at least two doses of mRNA vaccine was not associated with improved outcomes.

CONCLUSIONS

This study describes the natural history of SARS-CoV-2 infection in a large cohort of lung transplant recipients. Although one third of patients develop ALAD requiring augmented immunosuppression, infection with SARS-CoV-2 is not associated with worsening lung function.

Torque teno virus DNA load as a predictive marker of antibody response to a three-dose regimen of COVID-19 mRNA-based vaccine in lung transplant recipients

BACKGROUND

Previous studies have reported that lung transplant recipients (LTR) develop a poor response to two doses of COVID-19 vaccine, but data regarding the third dose are lacking. We investigated the antibody response after three doses of mRNA vaccine in LTR and its predictive factors.

METHODS

A total of 136 LTR, including 10 LTR previously infected and 126 COVID-19-naive LTR, were followed during and after three doses of mRNA vaccine. We retrospectively measured anti-receptor-binding domain (RBD) IgG response and neutralizing antibodies. In a posthoc analysis, we used a multivariate logistic regression model to assess the association between vaccine response and patient characteristics, including viral DNA load (VL) of the ubiquitous Torque teno virus (TTV) (optimal cut-off set by ROC curve analysis), which reflects the overall immunosuppression.

RESULTS

After 3 doses, 47/126 (37.3%) COVID-19-naive LTR had positive anti-RBD IgG (responders) and 14/126 (11.1%) had antibody titers above 264 Binding Antibody Units/mL. None neutralized the omicron variant versus 7 of the 10 previously infected LTR. Nonresponse was associated with TTV VL ≥6.2 log₁₀ copies/mL before vaccination (Odds Ratio (OR) = 17.87, 95% confidence interval (CI95) = 3.02-105.72), mycophenolate treatment (OR = 4.73, CI95 = 1.46-15.34) and BNT162b2 (n = 34; vs mRNA-1273, n = 101) vaccine (OR = 6.72, CI95 = 1.75-25.92). In second dose non-responders, TTV VL ≥6.2 or <3.2 log₁₀ copies/mL before the third dose was associated with low (0/19) and high (9/10) rates of seroconversion.

CONCLUSION

COVID-19-naive LTR respond poorly to three doses of mRNA vaccine, especially those with high TTV VL. Future studies could further evaluate this biomarker as a guide for vaccine strategies.

Improved immunogenicity following the third dose of BNT162b2 mRNA vaccine in heart transplant recipients

OBJECTIVES

The immunogenicity of two-dose severe acute respiratory syndrome coronavirus 2 vaccine is lower among heart transplant (HTx) recipients, compared with the general population. Our aim was to assess the immunogenicity of a third-dose vaccine in HTx recipients.

METHODS

This is a prospective cohort study of HTx recipients who received a third dose of the BNT162b2 vaccine. Immunogenicity was assessed by serum levels of anti-spike immunoglobulin G (S-IgG), taken at baseline and 14-28 days after the third dose. Titres above 50 U/ml were interpreted positive.

RESULTS

We Included 42 HTx recipients at a median age of 65 years [interquartile range (IQR) 58-70]. At baseline, the median of 27 days (IQR 13-42) before the third dose and the median titre of the whole group was 18 U/ml (IQR 4-130). Only 14 patients (33%) were S-IgG seropositive. After the third dose, the proportion of seropositive patients increased significantly to 57% (P = 0.05) and the median titre increased significantly to 633 U/ml (IQR 7-6104, P < 0.0001). Younger age at HTx (OR per 1-year decrease 1.07, P = 0.05), low tacrolimus serum level (OR per 1-unit decrease 2.28, P = 0.02), mammalian target of rapamycin use (OR 13.3, P = 0.003), lack of oral steroids use (OR 4.17, P = 0.04) and lack of calcineurin inhibitor use (71% of responders vs 100% non-responders received calcineurin inhibitors, P = 0.01) were predictors of seropositive result after the third dose. However, no significant association was detected following adjustment for baseline S-IgG titre.

CONCLUSIONS

Third-dose booster of BNT162b2 vaccine significantly increased immunogenicity among HTx recipients who previously received a two-dose vaccine.

Lung Transplant Recipients Immunogenicity after Heterologous ChAdOx1 nCoV-19—BNT162b2 mRNA Vaccination

(1) Background: High immunosuppressive regimen in lung transplant recipients (LTRs) hampers the immune response to vaccination. We prospectively investigated the immunogenicity of heterologous ChAdOx1 nCoV-19-BNT162b2 mRNA vaccination in an LTR cohort. (2) Methods: Forty-nine COVID-19 naïve LTRs received a two-dose regimen ChAdOx1 nCoV-19 vaccine. A subset of 32 patients received a booster dose of BNT162b2 mRNA vaccine 18 weeks after the second dose. (3) Results: Two-doses of ChAdOx1 nCoV-19 induced poor immunogenicity with 7.2% seropositivity at day 180 and low neutralizing capacities. The BNT162b2 mRNA vaccine induced significant increases in IgG titers with means of 197.8 binding antibody units per milliliter (BAU/mL) (95% CI 0–491.4) and neutralizing antibodies, with means of 76.6 AU/mL (95% CI 0–159.6). At day 238, 32.2% of LTRs seroconverted after the booster dose. Seroneutralization capacities against Delta and Omicron variants were found in only 13 and 9 LTRs, respectively. Mycophenolate mofetil and high-dose corticosteroids were associated with a weak serological response. (4) Conclusions: The immunogenicity of a two-dose ChAdOx1 nCoV-19 vaccine regimen was very poor in LTRs, but was significantly enhanced after the booster dose in one-third of LTRs. In immunocompromised individuals, the administration of a fourth dose may be considered to increase the immune response against SARS-CoV-2.

Third dose of the BNT162b2 vaccine in heart transplant recipients: Immunogenicity and clinical experience

BACKGROUND

The repeated waves of the COVID-19 pandemic have highlighted the necessity to optimize vaccine responses in immunocompromised populations. We investigated the safety and immunogenicity of a third, booster, dose of the Pfizer BNT162b2 vaccine in heart transplant (HT) patients.

METHODS

The cohort comprised 96 adult HT patients who received a third homologous dose of the BNT162b2 vaccine 168 days after the second dose. The vaccine-induced antibody responses of both receptor-binding domain (RBD) IgG and neutralizing antibodies were assessed in all patients, with a positive antibody response being defined as the presence of either IgG anti-RBD or neutralizing antibodies. For a subset of patients, T cell response was also studied.

RESULTS

The third dose was associated with a low rate of adverse events, mostly mild pain at the injection site. No serious adverse events were recorded, and there were no episodes of rejection. At 18 days following the third dose of the vaccine, the positive antibody response increased from 23% to 67%, with a corresponding increase in neutralizing capacity. The third dose elicited SARS-CoV-2 neutralization titers >9-fold and IgG anti-RBD antibodies >3-fold of the range achieved after the two primary doses. Mycophenolate use, lower eGFR and higher C-reactive protein were independently associated with a reduced likelihood of generating an immune response. Importantly, a specific T-cell response following the third dose was evident in the majority of transplant recipients.

CONCLUSIONS

An homologous third booster dose of the BNT162b2 vaccine gave overall consistent tolerability and a good safety profile, while eliciting humoral and cellular immune responses.

COVID-19 and Solid Organ Transplantation: Role of Anti-SARS-CoV-2 Monoclonal Antibodies

Purpose of Review

Solid organ transplant recipients (SOTRs) are ideal candidates for early treatment or prevention of coronavirus disease 2019 (COVID-19) using anti-SARS-CoV-2 monoclonal antibodies because of multiple underlying medical conditions, chronic immune-suppression, sub-optimal immunogenic response to vaccination, and evolving epidemiological risks. In this article, we review pertinent challenges regarding the management of COVID-19 in SOTRs, describe the role of active and passive immunity in the treatment and prevention of COVID-19, and review real-world data regarding the use of anti-SARS-CoV-2 monoclonal antibodies in SOTRs.

Recent Findings

The use of an anti-SARS-CoV-2 monoclonal antibody in high-risk solid organ transplant recipients is associated with a reduction in the risk of hospitalization, need for intensive care, and death related to COVID-19. Overall, the early experiences from a diverse population of solid organ transplant recipients who were treated with anti-spike monoclonal antibodies are encouraging with no reported acute graft injury, severe adverse events, or deaths related to COVID-19.

Summary

Anti-SARS-CoV-2 antibodies are currently authorized for treatment of mild-moderate COVID-19 and post-exposure prophylaxis, including in SOTRs. Potential future uses include pre-exposure prophylaxis in certain high-risk persons and synergistic use along with emerging oral treatment options. Successful timely administration of anti-SARS-CoV-2 monoclonal antibodies requires a multidisciplinary team approach, effective communication between patients and providers, awareness of circulating viral variants, acknowledgement of various biases affecting treatment, and close monitoring for efficacy and tolerability.

A Call for Caution in the Immunocompromised: Coronavirus Disease 2019 Associated With Mortality in a Vaccinated Lung Transplant Recipient

We describe a vaccinated lung transplant recipient who experienced a fatal outcome associated with coronavirus disease 2019 (COVID-19). Tocilizumab was administered. The patient exhibited clinical and radiographic evidence of colitis during the course of multiple secondary infections. This report emphasizes the need for more conservative precautions to prevent COVID-19 infection in transplant recipients.

COVID-19 vaccination coverage among healthcare workers in obstetrics and gynecology during the first three months of vaccination campaign: a cross-sectional study in Jiangsu province, China

Before the availability of COVID-19 vaccines, surveys showed that vaccine hesitancy may influence the acceptance of COVID-19 vaccination. In this cross-sectional study, we aimed to investigate COVID-19 vaccination coverage among healthcare workers (HCWs) in obstetrics and gynecology, during the first three-month period of the vaccination campaign after COVID-19 vaccines were approved. A total of 662 eligible HCWs, consisting of 250 HCWs (group one) who participated in a Jiangsu provincial symposium and 412 HCWs (group two) in the department of obstetrics and gynecology, Nanjing Drum Tower Hospital, were invited to answer a 23-question questionnaire. In total, 618 (93.4%) HCWs completed the questionnaire. The vaccine acceptance in group one was higher than that in group two (87.2% [197/226] vs 74.2% [291/392], χ2 = 14.436, P < .001). Overall, 488 (79.0%) HCWs received COVID-19 vaccination and 130 (21.0%) declined vaccination. One-third of the 488 vaccinees were not vaccinated until consulted with others or requested by employers. Adjusted logistic regression analysis showed that the decline of vaccination was associated with worry about the safety of the vaccine (OR 1.920, CI 95% 1.196-3.082; P = .007). The main reason for the decline of COVID-19 vaccination included the concern about vaccine safety, pregnancy preparation, pregnancy, or lactation. These results indicate that more safety data about COVID-19 vaccines, particularly in pregnant or lactating women, are required to promote the acceptance of COVID-19 vaccination. In addition, vaccination requests or mandates by employers may increase the acceptance of COVID-19 vaccines.

Humoral response to SARS-CoV-2 is well preserved and symptom dependent in kidney transplant recipients

Data on the immune response to SARS-CoV-2 in kidney transplant recipients are scarce. Thus, we conducted a single-center observational study to assess the anti-SARS-CoV-2 IgG seroprevalence in outpatient kidney transplant recipients (KTR; n = 1037) and healthcare workers (HCW; n = 512) during the second wave of the COVID-19 pandemic in fall 2020 and evaluated the clinical variables affecting antibody levels. Antibodies against S1 and S2 subunit of SARS-CoV-2 were evaluated using immunochemiluminescent assay (cut off 9.5 AU/ml, sensitivity of 91.2% and specificity of 90.2%). Anti-SARS-CoV-2 IgG seroprevalence was lower in KTR than in HCW (7% vs. 11.9%, p = .001). Kidney transplant recipients with SARS-CoV-2 infection were younger (p = .001) and received CNI-based immunosuppression more frequently (p = .029) than seronegative KTR. Anti-SARS-CoV-2 IgG positive symptomatic KTR had a higher BMI (p = .04) than asymptomatic KTR. Interestingly, anti-SARS-CoV-2 IgG levels were higher in KTR than in HCW (median 31 AU/ml, IQR 17-84 vs. median 15 AU/ml, IQR 11-39, p < .001). The presence of moderate to severe symptoms in KTR was found to be the only independent factor affecting IgG levels (Beta coefficient = 41.99, 95% CI 9.92-74.06, p = .011) in the multivariable model. In conclusion, KTR exhibit a well-preserved symptom-dependent humoral response to SARS-CoV-2 infection.

Predictors of Humoral Response to mRNA COVID19 Vaccines in Kidney Transplant Recipients: A Longitudinal Study-The COViNEPH Project

BACKGROUND

The efficacy of SARS-CoV-2 vaccination among kidney transplant recipients (KTR) is low. The main goal of this study was to analyze factors that may influence the humoral response to vaccination.

METHODS

We analyzed the titer magnitude of IgG antibodies directed against spike (S)-SARS-CoV-2 antigen after the second dose of the mRNA vaccine in 142 infection naïve KTR (83 men, i.e., 58.4%) with a median age (IQR) of 54 (41-63), and 36 respective controls without chronic kidney disease. mRNA-1273 or BNT162b2 were applied in 26% and 74% of KTR, respectively.

RESULTS

S-specific immune response (seroconversion) was seen in 73 (51.41%) of KTR, and in all controls 36 (100%). Independent predictors of no response were elder age, shorter transplantation vintage, and a more than two-drug immunosuppressive protocol. In subgroup analyses, the seroconversion rate was highest among KTR without MMF/MPS treatment (70%), treated with no more than two immunosuppressants (69.2%), treated without corticosteroid (66.7%), younger patients aged <54 years (63.2%), and those vaccinated with the mRNA-1273 vaccine (62.16%). The independent predictors of higher S-antibody titer among responders were younger age, treatment with no more than two immunosuppressants, and the mRNA-1273 vaccination.

CONCLUSIONS

Our study confirmed a low rate of seroconversion after vaccination with the mRNA vaccine in KTR. The major modifiable determinants of humoral response were the composition of the immunosuppressive protocol, as well as the type of vaccine. The latter could be taken into consideration when initial vaccination as well as booster vaccination is considered in KTR.

SARS-CoV-2 messenger RNA vaccine antibody response and reactogenicity in heart and lung transplant recipients

Background

While several studies have observed that solid organ transplant recipients experience diminished antibody responses to SARS-CoV-2 mRNA vaccination, data specific to heart and lung transplant (HT/LT) recipients remains sparse.

Methods

US adult HT and LT recipients completed their vaccine series between January 7 and April 10, 2021. Reactogencity and SARS-CoV-2 anti-spike antibody were assessed after a priming dose (D1) and booster dose (D2). Modified Poisson regression with robust variance estimator was used to evaluate associations between participant characteristics and antibody development.

Results

Of 134 heart recipients, there were 38% non-responders (D1-/D2-), 48% booster responders (D1-/D2+), and 14% priming dose responders (D1+/D2+). Of 103 lung recipients, 64% were non-responders, 27% were booster responders, and 9% were priming dose responders. Lung recipients were less likely to develop antibodies (p < .001). Priming dose antibody response was associated with younger recipient age (p = .04), transplant-to-vaccination time ≥6 years (p < .01), and lack of anti-metabolite maintenance immunosuppression (p < .001). Pain at injection site was the most commonly reported reaction (85% after D1, 76% after D2). Serious reactions were rare, the most common being fatigue (2% after D1 and 3% after D2). No serious adverse events were reported.

Conclusions

HT and LT recipients experienced diminished antibody response following vaccination; reactogenicity was comparable to that of the general population. LT recipients may exhibit a more impaired antibody response than HT recipients. While current recommendations are to vaccinate eligible candidates and recipients, further studies characterizing the cell-mediated immune response and clinical efficacy of these vaccines in this population are needed.