Review of Early Immune Response to SARS-CoV-2 Vaccination Among Patients With CKD

SARS-CoV-2-Specific Antibodies, B Cell and T Cell Immune Responses after ChAdOx1 nCoV-19 Vaccination in Solid Organ Transplant Recipients

BACKGROUND

Immunization against SARS-CoV-2 is essential for vulnerable solid organ transplant (SOT) recipients who are at risk of infection. However, there are concerns about suboptimal immunogenicity, especially in humoral immunity (HMI), and limited exploration of cell-mediated immune (CMI) responses. The primary objective of this study was to assess the immunogenicity of ChAdOx1 nCoV-19 vaccination in SOT recipients. The secondary endpoint was to evaluate factors that affect immunogenicity and adverse events (AEs) following immunization in SOT recipients.

METHODS

All adult SOT recipients who received the two-dose ChAdOx1 nCoV-19 vaccine at a 12-week interval underwent measurements of HMI by evaluating anti-receptor-binding domain (RBD) IgG levels and CMI by investigating SARS-CoV-2-specific T cell and B cell responses before and after complete vaccination, around 2-4 weeks post-vaccination, and compared to controls. AEs were monitored in all participants.

RESULTS

The study included 63 SOT recipients: 44 kidney recipients, 16 liver recipients, and 3 heart transplant recipients, along with 11 immunocompetent controls. Among SOT recipients, 36% were female, and the median (IQR) age was 52 (42-61). The median (IQR) time since transplant was 55 (28-123) months. After the second dose, the median (IQR) anti-RBD antibody levels were significantly lower in SOT recipients compared to those in the control group (8.3 [0.4-46.0] vs. 272.2 [178.1-551.6] BAU/mL, p < 0.01). This resulted in a seroconversion rate (anti-RBD antibody > 7.1 BAU/mL) of 51% among SOT recipients and 100% among controls (p = 0.008). Receiving the vaccine beyond one year post-transplant significantly affected seroconversion (OR 9.04, 95% CI 1.04-78.56, p = 0.046), and low-dose mycophenolic acid marginally affected seroconversion (OR 2.67, 95% CI 0.89-7.96, p = 0.079). RBD-specific B cell responses were also significantly lower compared to those in the control group (0 [0-4] vs. 10 [6-22] SFUs/106 PBMCs, p = 0.001). Similarly, S1- and SNMO-specific T cell responses were significantly lower compared to those in the control group (48 [16-128] vs. 216 [132-356] SFUs/106 PBMCs, p = 0.004 and 20 [4-48] vs. 92 [72-320] SFUs/106 PBMCs, p = 0.004). AEs were generally mild and spontaneously resolved.

CONCLUSIONS

SOT recipients who received the full two-dose ChAdOx1 nCoV-19 vaccine demonstrated significantly diminished HMI and CMI responses compared to immunocompetent individuals. Consideration should be given to administering additional vaccine doses or optimizing immunosuppressant regimens during vaccination (Thai Clinical Trial Registry: TCTR20210523002).

Effectiveness of Molnupiravir and Nirmatrelvir-Ritonavir in CKD Patients With COVID-19

Introduction

Even with effective vaccines, patients with CKD have a higher risk of hospitalization and death subsequent to COVID-19 infection than those without CKD. Molnupiravir and nirmatrelvir-ritonavir have been approved for emergency use, but their effectiveness for the CKD population is still unknown. This study was conducted to determine the effectiveness of these drugs in reducing mortality and severe COVID-19 in the CKD population.

Methods

This was a target trial emulation study using electronic health databases in Hong Kong. Patients with CKD aged 18 years or older who were hospitalized with COVID-19 were included. The per-protocol average treatment effect among COVID-19 oral antiviral initiators, including all-cause mortality, intensive care unit (ICU) admission, and ventilatory support within 28 days, were compared to noninitiators.

Results

Antivirals have been found to lower the risk of all-cause mortality, with Molnupiravir at a hazard ratio (HR) of 0.85 (95% confidence interval [CI], 0.77 to 0.95] and nirmatrelvir-ritonavir at an HR of 0.78 [95% CI, 0.60 to 1.00]. However, they do not significantly reduce the risk of ICU admission (molnupiravir: HR, 0.88 [95% CI, 0.59 to 1.30]; nirmatrelvir-ritonavir: HR, 0.86 [95% CI, 0.56 to 1.32]) or ventilatory support (molnupiravir: HR, 1.00 [95% CI, 0.76 to 1.33]; nirmatrelvir-ritonavir: HR, 1.01 [95% CI, 0.74 to 1.37]). There was a greater risk reduction in males and those with higher Charlson Comorbidity Index (CCI). The nirmatrelvir-ritonavir trial also showed reduced risk for those who had antiviral treatment and received 3 or more vaccine doses.

Conclusion

Both molnupiravir and nirmatrelvir-ritonavir reduced mortality rates for hospitalized COVID-19 patients with CKD.

Immune Response after Anti-SARS-CoV-2 mRNA Vaccination in Relation to Cellular Immunity, Vitamin D and Comorbidities in Hemodialysis Patients

In the global threat of SARS-CoV-2, individuals undergoing maintenance dialysis represent a vulnerable population with an increased risk of severe COVID-19 outcomes. Therefore, immunization against SARS-CoV-2 is an essential component of healthcare strategy for these patients. Existing data indicate that they tend to exhibit a reduced immune response to vaccines compared to the general population. Our study aimed to assess both humoral and cellular immune responses following two doses of an anti-SARS-CoV-2 mRNA vaccine, an ability to maintain adequate antibody titers over time, and potential relations with vitamin D, comorbidities and other factors in hemodialysis patients based on a single center experience. A total of 41/45 patients (91.1%) responded to the second dose of the anti-SARS-CoV-2 mRNA vaccine. The titer of anti-SARS-CoV-2 IgG class antibodies and levels of T cells three to four weeks after vaccination were lower in dialysis patients than in healthy controls. Antibodies titer in dialysis patients had a positive correlation with B lymphocytes and was related to cardiovascular diseases. The level of CD4+ cells had a negative correlation with hemodialysis vintage, as did the vitamin D level with post-vaccination seroconversion and decline in anti-SARS-CoV-2 antibodies titer during six months after vaccination. Hemodialysis patients had decreased amounts of CD4+ and CD8+ cells and lower levels of anti-SARS-CoV-2 antibodies than healthy controls. Therefore, chronic hemodialysis could lead to diminished cellular immunity and humoral immune response to the anti-SARS-CoV-2 mRNA vaccination and reduced protection from COVID-19. Comorbidity in cardiovascular diseases was associated with a lower level of specific anti-SARS-CoV-2 antibody titer. Vitamin D may be important in maintaining stable levels of anti-SARS-CoV-2 antibodies, while the duration of dialysis treatment could be one of the factors decreasing anti-SARS-CoV-2 antibody titer and determining lower CD4+ cell counts.

Vaccine Effectiveness of BNT162b2 and CoronaVac against SARS-CoV-2 Omicron BA.2 in CKD

BACKGROUND

The ongoing coronavirus disease 2019 (COVID-19) pandemic has posed increased risks of hospitalization and mortality in patients with underlying CKD. Current data on vaccine effectiveness of COVID-19 vaccines are limited to patients with CKD on dialysis and seroconversion in the non-dialysis population.

METHODS

A case-control study was conducted of adults with CKD using data extracted from the electronic health record database in Hong Kong. Adults with CKD and COVID-19 confirmed by PCR were included in the study. Each case was matched with up to ten controls attending Hospital Authority services without a diagnosis of COVID-19 on the basis of age, sex, and index date (within three calendar days). The vaccine effectiveness of BNT162b2 and CoronaVac in preventing COVID-19 infection, hospitalizations, and all-cause mortality was estimated using conditional logistic regression adjusted by patients' comorbidities and medication history during the outbreak from January to March 2022.

RESULTS

A total of 20,570 COVID-19 cases, 6604 COVID-19-related hospitalizations, and 2267 all-cause mortality were matched to 81,092, 62,803, and 21,348 controls, respectively. Compared with the unvaccinated group, three doses of BNT162b2 or CoronaVac were associated with a reduced risk of infection (BNT162b2: 64% [95% confidence interval (CI), 60 to 67], CoronaVac: 42% [95% CI, 38 to 47]), hospitalization (BNT162b2: 82% [95% CI, 77 to 85], CoronaVac: 80% [95% CI, 76 to 84]), and mortality (BNT162b2: 94% [95% CI, 88 to 97], CoronaVac: 93% [95% CI, 88 to 96]). Vaccines were less effective in preventing infection and hospitalization in the eGFR <15 and 15-29 ml/min per 1.73 m 2 subgroups as compared with higher GFR subgroups. However, receipt of vaccine, even for one dose, was effective in preventing all-cause mortality, with estimates similar to the higher eGFR subgroups, as compared with unvaccinated.

CONCLUSIONS

A dose-response relationship was observed between the number of BNT162b2 or CoronaVac doses and the effectiveness against COVID-19 infection and related comorbidity in the CKD population.

S. J, Balasubramanian CM, Devaraju PK, Murugesan V, P. S, Lamech TM, Arumugam V, Gopalakrishnan N. SARS-CoV-2 Antibody Seroprevalence and Humoral Response to Vaccination in Patients Undergoing Maintenance Hemodialysis: A Prospective Cohort Study

Introduction

COVID-19, caused by SARS-CoV-2, has resulted in significant mortality and morbidity worldwide. Patients of chronic kidney disease who are on maintenance hemodialysis represent a vulnerable population cohort that is susceptible to severe disease. Hence, it is of utmost importance to prioritize vaccination in this population and to assess their response to said vaccination.

Methods

This prospective analytical study was conducted at the Institute of Nephrology, Madras Medical College, between August 2021 and February 2022. Patients of chronic kidney disease stage 5 dialysis (CKD5D) who were on maintenance hemodialysis and who consented to receive COVID-19 vaccine were studied. Serum samples were obtained before vaccination, ≥28 days after receiving the first dose of the vaccine, and ≥28 days after receiving the second dose. Antibody titers against the spike protein were estimated using the Roche chemiluminescent immunosorbent assay. Patients were grouped into non-responders/seronegative (<0.8 U/ml) and responders/seropositive (≥0.8 U/ml), with a value ≥250 U/ml considered as robust response.

Results

A total of 96 patients were included. The mean age was 36.70 (±11.53) years and 77.1% of them were male. The median dialysis vintage was 2 (IQR: 0.95-5) years. Twelve patients (9.9%) had a prior COVID-19 infection. Sixty-seven (69.8%) patients had received Covaxin and 29 (30.2%) had received Covishield vaccines. Among the 17 patients who were seronegative at baseline, 4 (23.52%) became seropositive after the first dose of the vaccine, and 11 (64.7%) were seropositive after the second dose, with high titers ("robust response") achieved in two patients (11.76%). No antibody response, despite two doses of the vaccine, was noted in six patients (35.29%).

Conclusion

Our study showed a high baseline seropositivity rate, even prior to vaccination, which indicated a high rate of subclinical COVID infection. Among those who were seronegative at baseline, the seroconversion rate after two doses of Covaxin or Covishield was 64.70%.

Incidence and Severity of COVID-19 in Relation to Anti-Receptor-Binding Domain IgG Antibody Level after COVID-19 Vaccination in Kidney Transplant Recipients

Kidney transplant recipients (KTRs) elicit an impaired immune response after COVID-19 vaccination; however, the exact clinical impact remains unclear. We therefore analyse the relationship between antibody levels after vaccination and the risk of COVID-19 in a large cohort of KTRs. All KTRs living in the Netherlands were invited to send a blood sample 28 days after their second COVID-19 vaccination for measurement of their IgG antibodies against the receptor-binding domain of the SARS-CoV-2 spike protein (anti-RBD IgG). Information on COVID-19 was collected from the moment the blood sample was obtained until 6 months thereafter. Multivariable Cox and logistic regression analyses were performed to analyse which factors affected the occurrence and severity (i.e., hospitalization and/or death) of COVID-19. In total, 12,159 KTRs were approached, of whom 2885 were included in the analyses. Among those, 1578 (54.7%) became seropositive (i.e., anti-RBD IgG level >50 BAU/mL). Seropositivity was associated with a lower risk for COVID-19, also after adjusting for multiple confounders, including socio-economic status and adherence to COVID-19 restrictions (HR 0.37 (0.19-0.47), p = 0.005). When studied on a continuous scale, we observed a log-linear relationship between antibody level and the risk for COVID-19 (HR 0.52 (0.31-0.89), p = 0.02). Similar results were found for COVID-19 severity. In conclusion, antibody level after COVID-19 vaccination is associated in a log-linear manner with the occurrence and severity of COVID-19 in KTRs. This implies that if future vaccinations are indicated, the aim should be to reach for as high an antibody level as possible and not only seropositivity to protect this vulnerable patient group from disease.

ANCA-associated glomerulonephritis and lupus nephritis following COVID-19 vaccination: a case report and literature review

With the coverage of COVID-19 vaccination, it has been possible to observe the potential side effects of SARS-CoV-2 vaccines, with the most common ones being fever, myalgia, headache, and fatigue. However, an association has been observed between new and recurrent kidney injuries, mainly glomerulonephritis and lupus nephritis associated with ANCA, with the Pfizer-BioNTech, Moderna, Sinovac, and AstraZeneca vaccines, although the relationship between them is not clear. We report a case of ANCA-related vasculitis and lupus glomerulonephritis after the second dose of the AstraZeneca vaccine. The elderly patient presented significant worsening of kidney function after immunosuppression and complications after a new onset COVID-19 infection that led to death. We provide a literature review about kidney damage related to ANCA vasculitis after COVID-19 vaccine, aiming for a better understanding of the pathophysiological mechanism of kidney injury, its presentation, and treatment.

Evaluation of commercial assays for the assessment of SARS-CoV-2 antibody response in hemodialysis patients

BACKGROUND

Hemodialysis patients exhibit variable immunogenicity following administration of the SARS-CoV-2 mRNA vaccine. The aim of the current study was to evaluate the use of two commercial assays in the assessment of SARS-CoV-2 antibody response in hemodialysis patients and to compare their utility to commonly used SARS-CoV-2 serological assays developed in Canada.

METHODS

We evaluated serologic antibody response in 85 hemodialysis patients up to 6 months after receiving both doses of the Pfizer-BioNTech BNT162b2 COVID-19 mRNA vaccine. In addition, antibody response was assessed in 46 chronic kidney disease patients and 40 COVID-19 naïve health care workers (HCW) up to 3 months and 9 months, respectively. Anti-spike (S) and anti-nucleocapsid (N) levels were measured using Elecsys anti-SARS-CoV-2 immunoassays on the Roche analyzer and compared to ELISA-based detection of anti-S, anti-receptor binding domain (RBD), and anti-N.

RESULTS

The Elecsys anti-N immunoassay showed 93 % concordance with the anti-N ELISA. The Elecsys anti-S immunoassay showed 97 % concordance with the anti-S ELISA and 89 % concordance with the anti-RBD ELISA. HCWs exhibited significantly higher anti-S levels relative to hemodialysis patients. Anti-S levels decreased significantly over a 6-month period (p < 0.001) in patients receiving maintenance hemodialysis. In addition, anti-S levels decreased significantly over a 9-month (p < 0.001) and 3-month period (p < 0.001) in HCWs and CKD patients, respectively.

CONCLUSIONS

There is high concordance between commercial SARS-CoV-2 serological assays and SARS-CoV-2 serological assays developed in Canada. Hemodialysis patients exhibited varying immunogenicity following two doses of the COVID-19 mRNA vaccine with anti-S levels decreasing over time.

Comparative effectiveness of sotrovimab and molnupiravir for preventing severe COVID-19 outcomes in patients on kidney replacement therapy: observational study using the OpenSAFELY-UKRR and SRR databases

Background

Due to limited inclusion of patients on kidney replacement therapy (KRT) in clinical trials, the effectiveness of coronavirus disease 2019 (COVID-19) therapies in this population remains unclear. We sought to address this by comparing the effectiveness of sotrovimab against molnupiravir, two commonly used treatments for non-hospitalised KRT patients with COVID-19 in the UK.

Methods

With the approval of National Health Service England, we used routine clinical data from 24 million patients in England within the OpenSAFELY-TPP platform linked to the UK Renal Registry (UKRR) to identify patients on KRT. A Cox proportional hazards model was used to estimate hazard ratios (HRs) of sotrovimab versus molnupiravir with regards to COVID-19-related hospitalisations or deaths in the subsequent 28 days. We also conducted a complementary analysis using data from the Scottish Renal Registry (SRR).

Results

Among the 2367 kidney patients treated with sotrovimab (n = 1852) or molnupiravir (n = 515) between 16 December 2021 and 1 August 2022 in England, 38 cases (1.6%) of COVID-19-related hospitalisations/deaths were observed. Sotrovimab was associated with substantially lower outcome risk than molnupiravir {adjusted HR 0.35 [95% confidence interval (CI) 0.17-0.71]; P = .004}, with results remaining robust in multiple sensitivity analyses. In the SRR cohort, sotrovimab showed a trend toward lower outcome risk than molnupiravir [HR 0.39 (95% CI 0.13-1.21); P = .106]. In both datasets, sotrovimab had no evidence of an association with other hospitalisation/death compared with molnupiravir (HRs ranged from 0.73 to 1.29; P > .05).

Conclusions

In routine care of non-hospitalised patients with COVID-19 on KRT, sotrovimab was associated with a lower risk of severe COVID-19 outcomes compared with molnupiravir during Omicron waves.

COVID-19 Vaccine Antibody Response in a Single-Center Urban Hemodialysis Unit

BACKGROUND

The longitudinal response to the COVID-19 vaccines among patients on hemodialysis with and without prior SARS-CoV-2 infection has not been well characterized.

METHODS

To guide vaccination strategies in patients on hemodialysis, it is critical to characterize the longevity and efficacy of the vaccine; therefore, we conducted a prospective single-center monthly antibody surveillance study between March 2021 and March 2022 to investigate the dynamic humoral response to a series of COVID-19 mRNA vaccines in patients on hemodialysis with and without prior SARS-CoV-2 infection. Monthly quantitative antibody testing was performed using the Beckman Coulter Access SARS-CoV-2 IgG Antibody Test©, which detects IgG antibodies targeting the receptor binding domain (RBD) of the SARS-CoV-2 spike protein.

RESULTS

This cohort of 30 participants (mean age: 61 ± 3 years) predominantly self-identified as African American (97%) and male (53%). Eight participants (27%) had recovered from COVID-19 (recovered) before the vaccine initiation. All participants received two vaccine doses, and 86.6% received a 6-month booster dose. Among patients naïve to COVID-19, the antibody positivity rate (APR) was 55% post-first-dose, 91% post-second-dose, 50% pre-booster at 6 months, 100% post-booster, and 89% at 6 months post-booster. Recovered patients sustained a consistent 100% APR throughout the year. The naïve patients demonstrated lower peak antibody levels post-second-dose than the recovered patients (17.9 ± 3.2 vs. 44.7 ± 5.6, p < 0.001). The peak antibody levels post-booster showed no significant difference between both groups (27.1 ± 3.9 vs. 37.9 ± 8.2, p = 0.20). Two naïve patients contracted COVID-19 during the follow-up period.

CONCLUSIONS

The patients naïve to COVID-19 exhibited an attenuated and foreshortened antibody response following two doses of the mRNA vaccines compared with the recovered patients, who maintained 100% APR before the booster dose. The 6-month booster dose counteracted declining immunity and stimulated antibody responses in the naïve patients, even in previously non-responsive patients. This observation implies that different booster vaccination strategies might be required for COVID-19-naïve and -recovered patients. Post-vaccination antibody testing may serve as a valuable tool for guiding vaccination strategies.

Virus-Subtype-Specific Cellular and Humoral Immune Response to a COVID-19 mRNA Vaccine in Chronic Kidney Disease Patients and Renal Transplant Recipients

Patients with chronic kidney disease (CKD) or immunosuppression are at increased risk of severe SARS-CoV-2 infection. The vaccination of CKD patients has resulted in lower antibody concentrations and possibly reduced protection. However, little information is available on how T-cell-mediated immune response is affected in those patients and how vaccine-induced immune responses can neutralise different SARS-CoV-2 variants. Herein, we studied virus-specific humoral and cellular immune responses after two doses of mRNA-1273 (Moderna) vaccine in 42 patients suffering from CKD, small vessel vasculitis (maintenance phase), or kidney transplant recipients (KT). Serum and PBMCs from baseline and at three months after vaccination were used to determine SARS-CoV-2 S1-specific antibodies, neutralisation titers against SARS-CoV-2 WT, B1.617.2 (delta), and BA.1 (omicron) variants as well as virus-specific T-cells via IFNγ ELISpot assays. We observed a significant increase in quantitative and neutralising antibody titers against SARS-CoV-2 and significantly increased T-cell responses to SARS-CoV-2 S1 antigen after vaccination only in the CKD patients. In patients with vasculitis, neither humoral nor cellular responses were detected. In KT recipients, antibodies and virus neutralisation against WT and delta, but not against omicron BA.1, was assured. Importantly, we found no specific SARS-CoV-2 T-cell response in vasculitis and KT subjects, although unspecific T-cell activation was evident in most patients even before vaccination. While pre-dialysis CKD patients appear to mount an effective immune response for in vitro neutralisation of SARS-CoV-2, KT and vasculitis patients under immunosuppressive therapy were insufficiently protected from SARS-CoV-2 two months after the second dose of an mRNA vaccine.

Antibody response to COVID-19 vaccination in patients on chronic hemodialysis

Purpose

Since patients on hemodialysis (HD) are known to be vulnerable to coronavirus disease 2019 (COVID-19), many studies were conducted regarding the effectiveness of the COVID-19 vaccine in HD patients in Western countries. Here, we assessed antibody response of HD patients for 6 months post-vaccination to identify the duration and effectiveness of the COVID-19 vaccine in the Asian population.

Materials and Methods

We compared antibody response of the COVID-19 vaccine in HD patients with healthy volunteers. Patient and control groups had two doses of ChAdOx1 nCoV-19 and mRNA-1273, respectively. Immunoglobulin G (IgG) was measured before vaccination, 2 weeks after the first dose, 2 and 4 weeks, 3 and 6 months after the second dose. Neutralizing antibody was measured before vaccination and at 2 weeks, 3 and 6 months after second dose. Since the third dose was started in the middle of the study, we analyzed the effect of the third dose as well.

Results

Although antibody production was weaker than the control group (n=22), the patient group (n=39) showed an increase in IgG and neutralizing antibody after two doses. And, 21/39 patients and 14/22 participants had a third dose (BNT162b2 or mRNA-1273 in the patient group, mRNA-1273 in the control group), and it did not affect antibody response in both group. Trend analysis showed IgG and neutralizing antibody did not decrease over time. Age, sex, and HD vintage did not affect antibody production in HD patients. Patients with higher body mass index displayed better seroresponse, while those on immunosuppressants showed poor seroresponse.

Conclusion

Two doses of vaccination led to significant antibody response in HD patients, and the antibody did not wane until 6 months.

Management and Outcome of COVID-19 Infection Using Nirmatrelvir/Ritonavir in Kidney Transplant Patients

BACKGROUND

Nirmatrelvir/ritonavir has been shown to reduce the risk of COVID-19 related complications in patients at high risk for severe COVID-19. However, clinical experience of nirmatrelvir/ritonavir in the transplant recipient population is scattered due to the complex management of drug-drug interactions with calcineurin inhibitors. We describe the clinical experience with nirmatrelvir/ritonavir at The Ottawa Hospital kidney transplant program.

METHODS

Patients who received nirmatrelvir/ritonavir between April and June 2022 were included and followed up 30 days after completion of treatment. Tacrolimus was withheld for 24 hours and resumed 72 hours after the last dose of nirmatrelvir/ritonavir (on Day 8) based on drug level the day before. The first 30 patients had their dose adjusted according to drug levels performed twice in the first week and as needed thereafter. Subsequently, a simplified algorithm with less frequent calcineurin inhibitor level monitoring was implemented. Outcomes including tacrolimus level changes, serum creatinine and acute kidney injury (AKI, defined as serum creatinine increase by 30%) and clinical outcomes were described globally and compared between algorithms.

RESULTS

Fifty-one patients received nirmatrelvir/ritonavir. Tacrolimus levels drawn at the first timepoint, 7 days after withholding of calcineurin inhibitor and 2 days after discontinuing nirmatrelvir/ritonavir were within the therapeutic target in 17/44 (39%), subtherapeutic in 21/44(48%) and supratherapeutic in 6/44 (14%). Two weeks after, 55% were within the therapeutic range, 23% were below, and 23% were above it. The standard and simplified algorithms provided similar tacrolimus level (median 5.2 ug/L [4.0, 6.2] versus 4.8 ug/L [4.3, 5.7] p=0.70). There were no acute rejections or other complications.

CONCLUSIONS

Withholding tacrolimus starting the day before initiation of nirmatrelvir/ritonavir with resumption 3 days after completion of therapy resulted in a low incidence of supratherapeutic levels but a short period of subtherapeutic levels for many patients. AKI was infrequent. The data are limited by the small sample size and short follow-up.

Early Experience with Modified Dose Nirmatrelvir/Ritonavir in Dialysis Patients with Coronavirus Disease 2019

BACKGROUND

Nirmatrelvir/ritonavir was approved for use in high-risk outpatients with coronavirus disease 2019 (COVID-19). However, patients with severe CKD were excluded from the phase 3 trial, and the drug is not recommended for those with GFR <30 ml/min per 1.73 m 2 . On the basis of available pharmacological data, we developed a modified low-dose regimen of nirmatrelvir/ritonavir 300/100 mg on day 1, followed by 150/100 mg daily from day 2 to 5. In this study, we report our experience with this modified dose regimen in dialysis patients in the Canadian province of Ontario.

METHODS

We included dialysis patients who developed COVID-19 and were treated with the modified dose nirmatrelvir/ritonavir regimen during a 60-day period between April 1 and May 31, 2022. Details of nirmatrelvir/ritonavir use and outcomes were captured manually, and demographic data were obtained from a provincial database. Data are presented with descriptive statistics. The principal outcomes we describe are 30-day hospitalization, 30-day mortality, and required medication changes with the modified dose regimen.

RESULTS

A total of 134 dialysis patients with COVID-19 received nirmatrelvir/ritonavir during the period of study. Fifty-six percent were men, and the mean age was 64 years. Most common symptoms were cough and/or sore throat (60%). Medication interactions were common with calcium channel blockers, statins being the most frequent. Most patients (128, 96%) were able to complete the course of nirmatrelvir/ritonavir, and none of the patients who received nirmatrelvir/ritonavir died of COVID-19 in the 30 days of follow-up.

CONCLUSIONS

A modified dose of nirmatrelvir/ritonavir use was found to be safe and well tolerated, with no serious adverse events being observed in a small sample of maintenance dialysis patients.

COVID-19 in Elderly Patients Receiving Haemodialysis: A Current Review

There is an increased incidence of elderly adults diagnosed with kidney failure as our global aging population continues to expand. Hence, the number of elderly adults indicated for kidney replacement therapy is also increasing simultaneously. Haemodialysis initiation is more commonly observed in comparison to kidney transplantation and peritoneal dialysis for the elderly. The onset of the coronavirus 2019 (COVID-19) pandemic brought new paradigms and insights for the care of this patient population. Elderly patients receiving haemodialysis have been identified as high-risk groups for poor COVID-19 outcomes. Age, immunosenescence, impaired response to COVID-19 vaccination, increased exposure to sources of COVID-19 infection and thrombotic risks during dialysis are key factors which demonstrated significant associations with COVID-19 incidence, severity and mortality for this patient group. Recent findings suggest that preventative measures such as regular screening and, if needed, isolation in COVID-19-positive cases, alongside the fulfillment of COVID-19 vaccination programs is an integral strategy to reduce the number of COVID-19 cases and consequential complications from COVID-19, particularly for high-risk groups such as elderly haemodialysis patients. The COVID-19 pandemic brought about the rapid development and repurposing of a number of medications to treat patients in the viral and inflammatory stages of their disease. However, elderly haemodialysis patients were grossly unrepresented in many of these trials. We review the evidence for contemporary treatments for COVID-19 in this population to provide clinicians with an up-to-date guide. We hope our article increases awareness on the associations and impact of COVID-19 for the elderly haemodialysis population, and encourage research efforts to address knowledge gaps in this topical area.

COVID-19 und chronisch-entzündliche Darmerkrankungen

Die Pandemie durch die Coronavirus Disease 2019 (COVID-19) beeinflusst weiter das Leben von Patient*innen mit chronisch-entzündlichen Darmerkrankungen (CED). Umfangreiche Untersuchungen der letzten 3 Jahre ergaben, dass die allermeisten Infektionen durch „severe acute respiratory syndrome coronavirus type 2“ (SARS-CoV-2) bei CED-Patient*innen blande verlaufen. In der Regel wird die Krankheitsaktivität der CED nicht negativ beeinflusst; bei einem Teil der Patient*innen können passager gastrointestinale Symptome auftreten. Häufig eingesetzte immunmodulierende Medikamente hatten mit Ausnahme systemischer Glukokortikoide keinen Einfluss auf den Schweregrad einer COVID-19-Erkrankung und die Gesamtletalität unterschied sich nicht von der übrigen Bevölkerung. Die Impfantwort ist jedoch substanzabhängig erniedrigt. In dieser Übersichtsarbeit werden die wichtigsten Studien praxisrelevant zusammengefasst.

Cellular and Humoral Responses in Dialysis Patients after Vaccination with the BNT162b2 or mRNA-1273 Vaccines

The outbreak of SARS-CoV-2 has raised considerable concern about the detrimental effects it can induce in public health, with the interest of the scientific community being focused on the development of preventive and therapeutic approaches. Patients with end-stage renal disease (ESRD) are amongst vulnerable populations for critical illness owing to the presence of other comorbidities, their defective immune system, and their inability of self-isolation. To date, vaccination constitutes the most promising method to manage viral dispersion. Therefore, it is particularly important to investigate the effectiveness of available vaccines against SARS-CoV-2 in this risk group. Here, we summarize initial experience regarding the humoral and cellular immune responses elicited in dialysis patients after completion of the recommended vaccination regimen, as well as after booster dose administration, with one of the two mRNA vaccines, namely, BNT162b2 and mRNA-1273. In conclusion, a significantly diminished and delayed immune pattern was observed in ESRD patients compared to healthy population, with a peak in antibody titers occurring 3-5 weeks after the second dose. A booster dose significantly augmented the immune response in dialysis patients with either mRNA-based vaccine. Variables adversely correlating with the weak immunogenicity observed in dialysis patients include immunosuppressive therapy, older age, comorbidities, longer time in hemodialysis treatment, and higher body mass index. On the contrary, previous COVID-19 infection and administration of the mRNA-1273 vaccine are deemed to induce a more favorable immune response. Further investigation is needed to thoroughly understand the efficacy of mRNA-based vaccines in hemodialysis patients and define predictive factors that can influence it.

Immunogenicity of SARS-CoV-2 Vaccine in Kidney Transplant Recipients: A Cross-Sectional Study in Korea

Eighty-five Korean kidney transplant recipients who received three doses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine were tested with anti-receptor binding domain (RBD) antibody and neutralizing antibody. High anti-RBD antibody (≥ 100 U/mL) and neutralizing antibody responses (≥ 30%) were detected in 51/85 (60.0%) patients. When we divided the patients with the time from transplantation to vaccination (< 1, 1-2.4, 2.5-4.9, and ≥ 5-year), anti-RBD antibody titers were 3.2 U/mL, 27.8 U/mL, 370.2 U/mL, and 5,094.2 U/mL (P < 0.001) and anti-neutralizing antibody levels were 2.2%, 11.6%, 45.6%, and 93.0% (P < 0.001), respectively. Multivariate analysis revealed increased antibody responses when the time from transplantation to vaccination was five years or longer (odds ratio, 12.0; confidence interval, 2.7-52.8). Korean kidney transplant recipients had suboptimal antibody responses after the third dose of SARS-CoV-2 vaccine. A shorter time from transplantation to vaccination was a risk factor for a low antibody response.

Cellular and Humoral Responses to Recombinant and Inactivated SARS-CoV-2 Vaccines in CKD Patients: An Observational Study

BACKGROUND

It remains unclear what B cell and humoral responses are mounted by chronic kidney disease (CKD) patients in response to recombinant and inactivated SARS-CoV-2 vaccines. In this study, we aimed to explore the cellular and humoral responses, and the safety of recombinant and inactivated SARS-CoV-2 vaccines in CKD patients.

METHODS

79 CKD and 420 non-CKD individuals, who completed a full course of vaccination, were enrolled in the study. Adverse events (AEs) were collected via a questionnaire. Cellular and humoral responses were detected at 1, 3, and 6 months, including IgG antibody against the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein (anti-RBD-IgG), neutralizing antibodies (NAbs), the positive rate of NAbs and anti-RBD-IgG, RBD-atypical memory B cells (MBCs) (CD3 - CD19 + RBD + CD21 - CD27-), RBD-activated MBCs (CD3 - CD19 + RBD + CD21 - CD27+), RBD-resting MBCs (CD3 - CD19 + RBD + CD21 + CD27+), and RBD-intermediate MBCs (CD3 - CD19 + RBD + CD21 + CD27-).

RESULTS

We found no differences in the positivity rates of NAbs (70.89% vs. 79.49%, p = 0.212) and anti-RBD IgG (72.15% vs. 83.33%, p = 0.092) between the CKD and control groups. A total of 22 CKD individuals completed the full follow-up (1, 3, and 6 months). Significant and sustained declines were found at 3 months in anti-RBD IgG (26.64 BAU/mL vs. 9.08 BAU/mL, p < 0.001) and NAbs (161.60 IU/mL vs. 68.45 IU/mL p < 0.001), and at 6 months in anti-RBD IgG (9.08 BAU/mL vs. 5.40 BAU/mL, p = 0.064) and NAbs (68.45 IU/mL vs. 51.03 IU/mL, p = 0.001). Significant differences were identified in MBC subgroups between CKD patients and healthy controls, including RBD-specific atypical MBCs (60.5% vs. 17.9%, p < 0.001), RBD-specific activated MBCs (36.3% vs. 14.8%, p < 0.001), RBD-specific intermediate MBCs (1.24% vs. 42.6%, p < 0.001), and resting MBCs (1.34% vs. 22.4%, p < 0.001). Most AEs in CKD patients were mild (grade 1 and 2) and self-limiting. One patient with CKD presented with a recurrence of nephrotic syndrome after vaccination.

CONCLUSIONS

The recombinant and inactivated SARS-CoV-2 vaccine was well-tolerated and showed a good response in the CKD cohort. Our study also revealed differences in MBC subtypes after SARS-CoV-2 vaccination between CKD patients and healthy controls.

Humoral Response to BNT162b2 and CoronaVac in Patients Undergoing Maintenance Hemodialysis: A Multicenter Prospective Cohort Study

INTRODUCTION

Data regarding inactivated vaccines for SARS-CoV-2 in patients undergoing maintenance hemodialysis (MHD) are limited. We aimed to investigate humoral responses induced by CoronaVac compared to BNT162b2 in this population.

METHODS

In this multicenter prospective cohort study, adult patients undergoing MHD who lacked a history of COVID-19 and decided to get vaccinated with BNT162b2 or CoronaVac were enrolled. Participants provided serum samples before, 1 and 3 months after 2 doses. Anti-SARS-CoV-2 IgG antibodies against receptor-binding domain of the virus were measured, and levels ≥50 AU/mL were considered as positive. Breakthrough infections and adverse events were recorded.

RESULTS

Ninety-two patients were included, 68 (73.9%) of whom were seronegative at baseline. BNT162b2 and CoronaVac were administered in 38 (55.9%) and 30 (44.1%) patients. At 1 month, seropositivity was 93.1% in BNT162b2 and 88% in CoronaVac groups (p = 0.519). Quantitative antibody levels were significantly higher in BNT162b2 (p < 0.001). At 3 months, both seropositivity (96.4% and 78.3%, p = 0.045) and antibody levels (p = 0.001) remained higher in BNT162b2 compared to CoronaVac. Five patients (7.4%) experienced breakthrough COVID-19. Adverse events were more frequent with BNT162b2, although all of them were mild. Multiple linear regression model showed that only vaccine choice (BNT162b2) was related to the humoral response (β = 0.272, p = 0.038). Seropositive patients at baseline (n = 24) had higher antibody levels at any time point.

CONCLUSIONS

BNT162b2 and CoronaVac induced humoral responses in naïve patients undergoing MHD, which were more robust and durable for 3 months after BNT162b2. Both vaccines created high antibody levels in patients who were seropositive at baseline.

The immunologically high-risk kidney recipient in the early post-COVID-19 period. To do or not to do? A case report

Kidney transplantation is nowadays the treatment of choice for end-stage kidney disease (ESKD), and it is the most performed organ transplantation. During the COVID-19 pandemic, kidney-transplant recipients appeared to be at higher risk of morbidity and mortality due to severe forms of illness. The result was a decrease in the number of solid organs transplants worldwide, with patients' reduced chance of receiving transplants. The best timing for surgery after COVID-19 infection is still controversial since most of the available data come from study periods with zero or low prevalence of vaccination and COVID-19 variants with high mortality rates. The American Society of Anesthesiologists (ASA) and the Anesthesia Patient Safety Foundation (APSF) Joint Statement on Elective Surgery/Procedures and Anesthesia for Patients after COVID-19 Infection states that elective surgery should be delayed for 7 weeks after a SARS-CoV-2 infection in unvaccinated patients while making no clear statement for vaccinated ones, or those which have already been infected with the virus. Kidney transplant, as opposed to tissue transplant, is not an elective surgery, so the question raised is whether to do it or not. We present the case of a hyper-immunized 47-year-old male patient with end-stage chronic kidney disease who received a second kidney transplant, despite having a mild SARS-COV 2 infection just 2 weeks before his transplantation surgery.

Humoral response after BNT162b2 vaccine in Japanese hemodialysis patients

Background

Hemodialysis patients are more likely to be severely affected if infected by COVID-19. Contributing factors include chronic kidney disease, old age, hypertension, type 2 diabetes, heart disease, and cerebrovascular disease. Therefore, action against COVID-19 for hemodialysis patients is an urgent issue. Vaccines are effective in preventing COVID 19 infection. In hemodialysis patients, however, responses to hepatitis B and influenza vaccines are reportedly weak. The BNT162b2 vaccine has shown an efficacy rate of about 95% in the general population, but as far as we know there are only several reports of efficacy data in hemodialysis patients in Japan.

Methods

We assessed serum anti-SARS-CoV-2 IgG antibody (Abbott SARS-CoV-2 IgG II Quan) in 185 hemodialysis patients and 109 health care workers. The exclusion criterion was positivity for SARS-CoV-2 IgG antibody before vaccination. Adverse reactions to BNT162b2 vaccine were evaluated through interviews.

Results

Following vaccination, 97.6% of the hemodialysis group and 100% of the control group were positive for the anti-spike antibody. The median level of anti-spike antibody was 2,728.7 AU/mL (IQR, 1,024.2-7,688.2 AU/mL) in the hemodialysis group and 10,500 AU/ml (IQR, 9,346.1-2,4500 AU/mL) in the health care workers group. The factors involved in the low response to the BNT152b2 vaccine included old age, low BMI, low Cr index, low nPCR, low GNRI, low lymphocyte count, steroid administration, and complications related to blood disorders.

Conclusions

Humoral responses to BNT162b2 vaccine in hemodialysis patients are weaker than in a healthy control sample. Booster vaccination is necessary for hemodialysis patients, especially those showing a weak or non-response to the two-dose BNT162b2 vaccine.Trial registration UMIN, UMIN000047032. Registered 28 February 2022, https://center6.umin.ac.jp/cgi-bin/ctr/ctr_reg_rec.cgi.

Membranous Nephropathy following Full-Dose of Inactivated SARS-CoV-2 Virus Vaccination: A Case Report and Literature Review

Vaccination against the SARS-CoV-2 virus (COVID-19) has proven to be the most effective measure to prevent the spread and reduce infection severity. A case report of de novo membranous nephropathy (MN) following immunization with inactivated virus vaccine (CoronaVac^®, Sinovac Biotech) is presented here. A 53-year-old man presented with a sudden onset of leg edema a week after receiving an inactivated virus vaccine and a relapse of nephrotic syndrome (NS) with acute kidney injury (AKI) after a booster dose. Screening for serum anti-phospholipase A2 receptor antibody and secondary causes of MN were negative. Kidney biopsy revealed an early MN pattern with focal spike formation, whilst numerous subepithelial electron-dense deposits and a few small deposits in the mesangial area were observed through electron microscopy. A short course of steroids and oral cyclophosphamide was prescribed, resulting in the complete remission of NS and AKI. MN following SARS-CoV-2 vaccination should call for medical importance. Awareness of the association between vaccination and MN should be kept in mind to avoid unnecessary treatment with long-term immunosuppressive agents.

Effectiveness of Messenger RNA Vaccines against SARS-CoV-2 Infection in Hemodialysis Patients: A Case-Control Study

Patients with end-stage kidney disease (ESKD) are at increased risk for SARS-CoV-2 infection and its complications compared with the general population. Several studies evaluated the effectiveness of COVID-19 vaccines in the dialysis population but showed mixed results. The aim of this study was to determine the effectiveness of COVID-19 mRNA vaccines against confirmed SARS-CoV-2 infection in hemodialysis (HD) patients in the State of Qatar. We included all adult ESKD patients on chronic HD who had at least one SARS-CoV-2 PCR test done after the introduction of the COVID-19 mRNA vaccines on 24 December 2020. Vaccinated patients who were only tested before receiving any dose of their COVID-19 vaccine or within 14 days after receiving the first vaccine dose were excluded from the study. We used a test-negative case−control design to determine the effectiveness of the COVID-19 vaccination. Sixty-eight patients had positive SARS-CoV-2 PCR tests (cases), while 714 patients had negative tests (controls). Ninety-one percent of patients received the COVID-19 mRNA vaccine. Compared with the controls, the cases were more likely to be older (62 ± 14 vs. 57 ± 15, p = 0.02), on dialysis for more than one year (84% vs. 72%, p = 0.03), unvaccinated (46% vs. 5%, p < 0.0001), and symptomatic (54% vs. 21%, p < 0.0001). The effectiveness of receiving two doses of COVID-19 mRNA vaccines against confirmed SARS-CoV-2 infection was 94.7% (95% CI: 89.9−97.2) in our HD population. The findings of this study support the importance of using the COVID-19 mRNA vaccine in chronic HD patients to prevent SARS-CoV-2 infection in such a high-risk population.

[Inflammatory bowel disease during the COVID-19 pandemic: manifestations and management]

The COVID-19 pandemic is significantly affecting the lives of patients with inflammatory bowel disease (IBD). Those affected and their relatives have numerous questions about the risk of the disease, the course of a possible SARS-CoV-2 infection or the influence of CED-specific therapy on these. Many IBD patients also have additional questions about the safety and effectiveness of a vaccination against SARS-CoV-2. The aim of this review is to summarize the latest findings on COVID-19 and IBD, but also to discuss vaccine response (humoral/cellular), the influence of ongoing therapy on the vaccine response as well as the frequency of side effects and the importance of booster immunizations and to create an evidence-based basis for discussion with patients.

Impact of ABO Compatibility/Incompatibility on the Perioperative Anti-SARS-CoV-2 Immunoglobulin G Levels in 2 Preoperatively Vaccinated Patients Undergoing Kidney Transplant: A Case Report

Herein, we monitored the perioperative anti-SARS-CoV-2 spike immunoglobulin G titers in patients who were preoperatively vaccinated with 2 doses of a COVID-19 messenger RNA vaccine. Additionally, we compared the clinical settings between ABO-incompatible and ABO-compatible pre-emptive kidney transplant (KTx). Case 1 was of a 45-year-old man who was an ABO-incompatible KTx recipient. Before transplant, his serum antibody titers decreased from 278 U/mL at baseline to 41.9 U/mL after desensitization therapy (84.9% lower) and 54.7 U/mL (80.3% lower) at day 8; it is now maintained at 4.1 U/mL at 6 months posttransplant (98.5% lower). Case 2 was of a 50-year-old man who was an ABO-compatible KTx recipient. His serum antibody titer level decreased from 786 U/mL at baseline to 386 U/mL on day 8 (50.8% lower) and is now maintained at 156 U/mL at 6 months posttransplant (80.1% lower). We suggest that anti-SARS-CoV-2 spike immunoglobulin G titers should be monitored during the perioperative period to determine the optimal timing of COVID-19 vaccine booster doses for the maintenance of protective immunity, particularly in ABO-incompatible KTx recipients who require desensitization therapy.

Immune Response to Third and Fourth COVID-19 Vaccination in Hemodialysis Patients and Kidney Transplant Recipients

Severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) is a serious hazard for hemodialysis (HD) patients and kidney transplant (KTX) recipients as they suffer from an impaired immune response to SARS-CoV-2 vaccination. In addition, a definition of SARS-CoV-2 IgG titer that indicates a sufficient immune response, especially against new omicron variants, is urgently needed. In the present study, the immune response to either a third or a fourth dose of a mRNA vaccine was investigated in 309 dialysis and 36 KTX patients. SARS-CoV-2 IgG titer thresholds indicating neutralizing activity against wild type (WT) and the omicron variant BA.1 were quantified. After four vaccine doses, a high-neutralizing activity against WT was evidenced in HD patients, whereas the neutralizing rate against BA.1 was significant lower. Concerning KTX recipients, humoral and cellular immune responses after a third vaccination were still highly impaired. This calls for modified omicron-targeting vaccines.

Immunogenicity of the Two mRNA SARS-CoV-2 Vaccines in a Large Cohort of Dialysis Patients

Chronic kidney disease patients, especially those on hemodialysis, are at the highest risk of a severe course and death from COVID-19. Moreover, they appear to have suboptimal response in both cellular and humoral immunity after vaccination. The present study investigated humoral and cellular response and safety after two doses of either of the two authorized mRNA vaccines in a cohort of 310 patients on maintenance dialysis. The antibody response rate was 94.5%, with a median (25th, 75th) antibody titer of 3478 (1236, 8141) AU/mL. Only mild adverse effects were observed. Only vaccine type was independently associated with immunogenicity. Α statistically significant difference in favor of mRNA1273 versus BNT162b2 vaccine was observed. Antibody positivity (100% vs. 94.3%, p < 0.001), median (25th, 75th) antibody levels: 9499 (6118, 20,780) AU/mL vs. 3269 (1220, 7807) AU/mL (p < 0.001). Among the 65 patients tested for T-cell response, 27 (41.5%) had a positive one with a median (25th, 75th) antibody titer of 6007 (3405, 12,068) AU/mL, while 38 with no T-cell response presented a lower median (25th, 75th) antibody titer of 1744 (850, 4176) AU/mL (p < 0.001). Both mRNA vaccines are safe for dialysis patients and can trigger humoral and cellular responses, although with lower titers than those that have been reported to healthy individuals.

Immunogenicity After a Heterologous BNT262b2 Versus Homologous Booster in Kidney Transplant Recipients Receiving 2 Doses of CoronaVac Vaccine: A Prospective Cohort Study

BACKGROUND

Comparative studies of third heterologous doses following the CoronaVac vaccine against coronavirus disease 2019 (COVID-19) in kidney transplant recipients are lacking.

METHODS

This prospective, single-center cohort study included kidney transplant recipients without previous COVID-19. Patients received a third heterologous (BNT162b2 mRNA) or homologous dose at least 4 wk after 2 doses of the CoronaVac vaccine. Immunoglobulin G antibody response and seroprevalence for neutralizing anti-severe acute respiratory syndrome coronavirus 2 antibodies immediately before and 28 d after third doses were compared between the groups.

RESULTS

There were 307 patients in the heterologous group and 777 in the homologous group. Patients in the heterologous group were older (54 versus 50 y; P < 0.0001), with a longer time since transplant (11 versus 6 y; P < 0.0001). Immediately before the third dose, immunoglobulin G seroprevalence (36% versus 34%; P = 0.597) and antibody titers (246 versus 268 AU/mL; P = 0.279) were similar. After booster, seroconversion was higher in the heterologous group (49% versus 32%; P < 0.0001), resulting in a higher seroprevalence (67% versus 55%; P = 0.0003); however, 42% of all patients remained seronegative. Antibody titers after booster in seropositive patients were higher in the heterologous group (7771 versus 599 AU/mL; P < 0.0001). These results persisted after adjusting for confounding variables. Lastly, a similar proportion of patients became seropositive for neutralizing antibodies (98% versus 94%; P = 0.098).

CONCLUSIONS

In kidney transplant recipients fully vaccinated with CoronaVac, a third dose with an mRNA vaccine produced a higher seroconversion rate and antibody titers than a third homologous dose. However, both boosters achieved equivalent seroprevalence for neutralizing antibodies. The high proportion of still seronegative patients indicates the need for alternative strategies of protection.

SARS-CoV-2 spike protein antibody titers 6 months after SARS-CoV-2 mRNA vaccination among patients undergoing hemodialysis in Japan

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination is shown to prevent severe illness and death in hemodialysis (HD) patients, but the immune response to vaccines is reduced in this population. This study compared SARS-CoV-2 spike protein antibody titers between HD patients and healthy controls in Japan for up to 6 months following vaccination.

METHODS

A multi-institutional retrospective study at five clinics in Japan was conducted using 412 HD patients and 156 healthy controls who received two doses of the BNT162b2 (Pfizer-BioNTech) mRNA vaccine. Anti-SARS-CoV-2 spike protein S1 IgG antibody titers were measured at 1, 3, and 6 months after the second dose. The attenuation speed was calculated as slope (i.e., -β) using a linear mixed-effects model toward the log-transformed antibody titers.

RESULTS

The HD group had significantly lower month 1 antibody titers (Ab-titer-1) than the controls, and these remained lower through month 6 (95% CI: 2617.1 (1296.7, 5240.8) vs. 7285.4 (4403.9, 11,000.0) AU/mL at Ab-titer-1, and 353.4 (178.4, 656.3) vs. 812.0 (498.3, 1342.7) AU/mL at Ab-titer-6 (p < 0.001, respectively)). Lower log Ab-titer-1 levels in the HD group were significantly associated with a lower log Ab-titer-6 (0.90 [0.83, 0.97], p < 0.001). The -β values in the HD patients and healthy controls were -4.7 ± 1.1 and -4.7 ± 1.4 (year-1), respectively.

CONCLUSION

SARS-CoV-2 spike protein antibody titers were significantly lower in HD patients than in healthy controls at 1 (peak) and 6 months after the second vaccination. Low peak antibody titers contributed to low 6-month antibody titers.

The Waxing, Waning, and Predictors of Humoral Responses to Vector-Based SARS-CoV-2 Vaccine in Hemodialysis Patients

Hemodialysis (HD) patients are vulnerable to coronavirus disease 2019 (COVID-19) and have a high mortality rate. We evaluated the anti-SARS-CoV-2 spike protein antibody (ACOV2S) levels in 385 HD patients before and 4 and 8 weeks after the second dose of vector-based ChAdOx1 nCoV-19 vaccine. For study control, week 4 ACOV2S levels after the second vaccination dose were measured in 66 healthcare workers (HCWs). The seroconversion rate of HD patients was 98.96% 4 weeks after the second vaccination. Despite low antibody levels before the second dose (week 0), week 4 ACOV2S levels after the second vaccine dose in HD patients increased prominently and were compatible with those in HCWs (p = 0.814 for HCWs vs. HD patients). The ACOV2S levels in HD patients waned significantly 8 weeks after the second vaccination dose (p < 0.001 at week 8 vs. 4). Older age and immunosuppressant use were negative predictors, while higher C-reactive protein (CRP) levels were positive predictors of ACOV2S waxing after the second vaccine dose in HD patients. Higher CRP levels and platelet counts were independently associated with decreased ACOV2S waning. The ChAdOx1 nCoV-19 vaccine is effective and safe for primary vaccination in HD patients and a booster dose is necessary.

COVID-19 Infection and Response to Vaccination in Chronic Kidney Disease and Renal Transplantation: A Brief Presentation

Chronic kidney disease (CKD) is associated with phenotypic and functional changes in the immune system, followed by detrimental clinical consequences, such as severe infections and defective response to vaccination. Two years of the pandemic, due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), have undoubtedly changed the world; however, all efforts to confront infection and provide new generation vaccines tremendously improved our understanding of the mechanisms of the immune response against infections and after vaccination. Humoral and cellular responses to vaccines, including mRNA vaccines, are apparently affected in CKD patients, as elimination of recent thymic emigrant and naïve lymphocytes and regulatory T-cells, together with contraction of T-cell repertoire and homeostatic proliferation rate, which characterized CKD patients are responsible for impaired immune activation. Successful renal transplantation will restore some of these changes, although several epigenetic changes are irreversible and even accelerated by the induction of immunosuppression. Response to vaccination is definitely impaired among both CKD and RT patients. In the present review, we analyzed the differences in immune response after vaccination between these patients and healthy individuals and depicted specific parameters, such as alterations in the immune system, predisposing to this deficient response.

Humoral Response Following Triple Dose of mRNA Vaccines Against SARS-CoV-2 in Hemodialysis Patients: Results After 1 Year of Follow-Up

Introduction

COVID-19 is associated with an increased mortality in hemodialysis patients. Therefore, achieving a long-lasting effective immune response to SARS-CoV-2 vaccines is essential. This study describes the humoral immune response in hemodialysis patients following three doses of mRNA vaccines against SARS-CoV-2, and explores the factors associated with a sustained immune response.

Materials and Methods

We analyzed the monthly serological evolution of SARS-CoV-2 anti-S(RBD) antibodies for 1 year in 178 chronic hemodialysis patients who received three doses of SARS-CoV-2 mRNA vaccines. The primary outcome was sustained effective humoral response defined as anti-S(RBD) levels > 1,000 AU/ml after 4 months from the third dose. Multivariate logistic regression analyses were used to identify features associated with a sustained humoral immune response.

Results

After the initial two SARS-CoV-2 mRNA vaccine doses, 77.8% of patients showed an immediate effective humoral response, decreasing to 52.5% after 4 months. Antibody levels were significantly higher in COVID-exposed patients and HBV vaccine responders. After the third dose, 97% of patients showed an effective humoral response, and remained in 91.7% after 4 months. The mean monthly rate of antibody titer decline decreased from 33 ± 14.5 to 25 ± 16.7%. Multivariate regression analysis showed that previous exposure to COVID-19 and response to HBV vaccines were associated with an effective sustained humoral immune response.

Conclusion

Immunization with SARS-CoV-2 mRNA vaccines elicits an effective immediate humoral immune response in hemodialysis patients, with a progressive waning in antibody levels. A third booster dose enhances the immune response with significantly higher antibody levels and more sustained humoral immune response. COVID-naïve patients and patients without previous response to HBV vaccines are likely to benefit from receiving more booster doses to maintain an effective immune response.

Benefit-risk evaluation of COVID-19 vaccination in special population groups of interest

Several population groups display an increased risk of severe disease and mortality following SARS-CoV-2 infection. These include those who are immunocompromised (IC), have a cancer diagnosis, human immunodeficiency virus (HIV) infection or chronic inflammatory disease including autoimmune disease, primary immunodeficiencies, and those with kidney or liver disease. As such, improved understanding of the course of COVID-19 disease, as well as the efficacy, safety, and benefit-risk profiles of COVID-19 vaccines in these vulnerable groups is paramount in order to inform health policy makers and identify evidence-based vaccination strategies. In this review, we seek to summarize current data, including recommendations by national health authorities, on the impact and benefit-risk profiles of COVID-19 vaccination in these populations. Moving forward, although significant efforts have been made to elucidate and characterize COVID-19 disease course and vaccine responses in these groups, further larger-scale and longer-term evaluation will be instrumental to help further guide management and vaccination strategies, particularly given concerns about waning of vaccine-induced immunity and the recent surge of transmission with SARS-CoV-2 variants of concern.

Ethical Issues in Kidney Transplant and Donation During COVID-19 Pandemic

The coronavirus disease-19 pandemic caused by the severe acute respiratory syndrome coronavirus has faced the transplant community with unprecedented clinical challenges in a highly vulnerable patient category. These were associated with many uncertainties for patients and health care professionals and prompted many ethical debates regarding the safe delivery of kidney transplantation. In this article, we highlight some of the most important ethical questions that were raised during the pandemic and attempt to analyze ethical arguments in light of core principles of medical ethics to either suspend or continue kidney transplantation, and to mandate vaccination in transplant patients, transplant candidates, and, finally, health care providers. We have come up with frameworks to deal responsibly with these ethical challenges, and formulated recommendations to cope with the issues imposed on patients and transplant professionals.

Humoral Response to mRNA-1273 SARS-CoV-2 Vaccine in Peritoneal Dialysis Patients: Is Boostering After Six Months Adequate?

In dialysis patients the humoral response to anti-SARS-CoV-2 vaccines is attenuated and rapidly declines over time. However, data on the persistence of the immune response in peritoneal dialysis (PD) patients are scarce, particularly after a third (booster) dose with mRNA-1273 vaccine. In this prospective cohort study, we report anti-SARS-CoV-2 antibody levels in PD patients before and after the third dose of mRNA-1273 vaccine. Six months after the second dose, anti-SARS-CoV-2 antibodies were detected in all patients (n = 34). However, within this time period antibodies substantially declined in 31 of 34 patients (4.5-fold, median = 192 BAU/mL, p = 1.27 × 10^–9) and increased in three patients. In accordance with government regulations, a third dose of mRNA-1273 vaccine (50 μg) was given to 27 PD patients 6 months after the second dose which induced a significant increase of anti-SARS-CoV-2 antibody titers (58.6-fold, median = 19405 BAU/mL, p = 1.24 × 10^–29). A mixed model analysis showed that a lower Davies Comorbidity Score and a higher GFR were associated with higher antibody titers (p = 0.03 and p = 0.02). The most common adverse events after the third dose were pain at the injection site (77.8%) and fatigue (51.9%). No hospitalizations were reported. In conclusion, 6 months after the second dose of mRNA-1273 vaccine, anti-SARS-CoV-2 antibodies substantially decreased in PD patients, whereas a well-tolerated third dose induced a robust humoral response. Our data suggest that the administration of a booster dose within a shorter interval than 6 months should be considered in PD patients in order to maintain high anti-SARS-CoV-2 antibody levels and assure protection from severe COVID-19 disease.

Effect of Third and Fourth mRNA-Based Booster Vaccinations on SARS-CoV-2 Neutralizing Antibody Titer Formation, Risk Factors for Non-Response, and Outcome after SARS-CoV-2 Omicron Breakthrough Infections in Patients on Chronic Hemodialysis: A Prospective Multicenter Cohort Study

The aim of this study is to determine the effect of repeated vaccinations on neutralizing SARS-CoV-2 IgG antibody titers, evaluate risk factors for immunological non-response, and to report breakthrough infections in chronic hemodialysis patients. Methods: A prospective, multi-center cohort study in 163 chronic hemodialysis patients was conducted. Antibody titers were measured three months after second, third, and fourth (10 pts) booster vaccinations. SARS-CoV-2 neutralizing antibody titers in BAU/mL and % inhibition were divided into three categories (<216, 216–433, >433 and <33, 33–66, and >66%). Somers’s test, paired t-test, and univariable and multivariable logistic regression analysis were applied to evaluate differences in antibody levels and search for risk factors for vaccination failure defined as neutralizing titers <50% and/or need for repeated booster vaccinations. Furthermore, we report on a case series to describe characteristics of patients after four vaccinations (n = 10) and breakthrough infections (n = 20). Results: Third dose boosters resulted in higher proportions of patients with neutralizing antibody levels >66% as compared to after the second dose (64.7% after second dose vs. 88.9% after third dose, p = 0.003), as well as in a respective increase in neutralizing titer levels in % from 68 ± 33% to 89 ± 24 (p < 0.001). The proportion of patients with IgG-titers below 216 BAU/mL decreased from 38.6 to 10.5% (p ≤ 0.001). Age (p = 0.004, OR 1.066, 95% CI 1.020–1.114) and presence of immunosuppressive medications (p = 0.002, OR 8.267, 95% CI 2.206–30.975) were identified as major risk factors for vaccination failure. Repeated booster vaccinations ≥4 times were effective in 8 out of 10 former low-responders (80%) without any side effects or safety concerns. Breakthrough infections showed a clinically mild course but were associated with prolonged viral shedding on PCR-testing ranging 7–29 (mean 13) days. Conclusions: Third and fourth mRNA-based booster vaccinations resulted in higher and longer lasting SARS-CoV-2 antibody levels as compared to after two dosages. The presence of immunosuppressive medication and repeat vaccinations are major potentially modifiable measures to increase antibody levels in non-or low-responders. Breakthrough infections with SARS-CoV-2 Omicron were associated with prolonged viral shedding but clinically mild disease courses.

SARS-COV-2 vaccine responses in renal patient populations

Background

Dialysis patients and immunosuppressed renal patients are at increased risk of COVID-19 and were excluded from vaccine trials. We conducted a prospective multicentre study to assess SARS-CoV-2 vaccine antibody responses in dialysis patients and renal transplant recipients, and patients receiving immunosuppression for autoimmune disease.

Methods

Patients were recruited from three UK centres (ethics:20/EM/0180) and compared to healthy controls (ethics:17/EE/0025). SARS-CoV-2 IgG antibodies to spike protein were measured using a multiplex Luminex assay, after first and second doses of Pfizer BioNTech BNT162b2(Pfizer) or Oxford-AstraZeneca ChAdOx1nCoV-19(AZ) vaccine.

Results

Six hundred ninety-two patients were included (260 dialysis, 209 transplant, 223 autoimmune disease (prior rituximab 128(57%)) and 144 healthy controls. 299(43%) patients received Pfizer vaccine and 379(55%) received AZ. Following two vaccine doses, positive responses occurred in 96% dialysis, 52% transplant, 70% autoimmune patients and 100% of healthy controls. In dialysis patients, higher antibody responses were observed with the Pfizer vaccination. Predictors of poor antibody response were triple immunosuppression (adjusted odds ratio [aOR]0.016;95%CI0.002–0.13;p < 0.001) and mycophenolate mofetil (MMF) (aOR0.2;95%CI 0.1–0.42;p < 0.001) in transplant patients; rituximab within 12 months in autoimmune patients (aOR0.29;95%CI 0.008–0.096;p < 0.001) and patients receiving immunosuppression with eGFR 15-29 ml/min (aOR0.031;95%CI 0.11–0.84;p = 0.021). Lower antibody responses were associated with a higher chance of a breakthrough infection.

Conclusions

Amongst dialysis, kidney transplant and autoimmune populations SARS-CoV-2 vaccine antibody responses are reduced compared to healthy controls. A reduced response to vaccination was associated with rituximab, MMF, triple immunosuppression CKD stage 4. Vaccine responses increased after the second dose, suggesting low-responder groups should be prioritised for repeated vaccination. Greater antibody responses were observed with the mRNA Pfizer vaccine compared to adenovirus AZ vaccine in dialysis patients suggesting that Pfizer SARS-CoV-2 vaccine should be the preferred vaccine choice in this sub-group.

Adequacy of Hemodialysis Serves as an Independent Predictor of Humoral Response to ChAdOx1 Prime-Boost Vaccination in Hemodialysis Patients

Background: Immune response assessed by the quantification of neutralizing antibodies (nAbs) and predictors associated with immunogenicity after the prime-boost ChAdOx1 (Oxford−AstraZeneca) COVID-19 vaccine in hemodialysis (HD) patients remains unclear. Methods: This prospective study enrolled 174 HD patients and 67 healthy subjects to evaluate antibodies against the spike protein 1 and receptor-binding domain of severe acute respiratory syndrome coronavirus type 2 after prime-booster vaccination, by using enzyme-linked immunosorbent assay and applied spline-based generalized additive model regression analysis to predict 50% neutralization titer (NT50). The correlation between HD parameters and NT50 was analyzed. Results: NT50 was lower in HD patients compared with healthy controls after the prime-boost dose (p < 0.001). The geometric mean titer ratios were higher in first-dose seronegative than in the seropositive subgroup in HD patients and healthy controls (6.96 vs. 2.36, p = 0.002, and 9.28 vs. 1.26, p = 0.011, respectively). After two doses of ChAdOx1, one-way ANOVA showed that Ca × P was positively associated with NT50 (p trend = 0.043) and multiple linear regression showed the similar results (p = 0.021). Kt/V (a quantification of dialysis adequacy) (OR = 20.295, p = 0.005) could independently predict seroconversion (NT50 ≥ 35.13 IU/mL). Conclusion: Adequacy of hemodialysis could independently predict seroconversion in HD subjects vaccinated with prime-boost doses of ChAdOx1.

COVID-19 in dialysis: clinical impact, immune response, prevention, and treatment

The COVID-19 pandemic has profound adverse effects on the population on dialysis. Patients requiring dialysis are at an increased risk of SARS-CoV-2 infection and mortality, and many have experienced psychological distress as well as delayed or suboptimal care. COVID-19 survivors have prolonged viral shedding, but generally develop a robust and long-lasting humoral immune response that correlates with initial disease severity. However, protection against reinfection is incomplete. A growing body of evidence reveals delayed and blunted immune responses to SARS-CoV-2 vaccination. Administration of a third dose within 1 to 2 months of prime-boost vaccination significantly increases antibody levels, in particular in patients with poor initial responses. Patients on dialysis have inferior immune responses to adenoviral vector vaccines than to mRNA vaccines. The immunogenicity of the mRNA-1273 vaccine is markedly better than that of the BNT162b2 vaccine, most likely by virtue of its higher mRNA content. Despite suboptimal immune responses in patients on dialysis, preliminary data suggest that vaccination partially protects against infection and severe disease requiring hospitalization. However, progressive waning of immunity and emergence of SARS-CoV-2 variants with a high potential of immune escape call for a booster dose in all patients on dialysis 4 to 6 months after prime-boost vaccination. Patients with persistent poor vaccine responses may be candidates for primary prophylaxis strategies. In the absence of specific data in patients on dialysis, therapeutic strategies in the event of established COVID-19 must be extrapolated from evidence obtained in the population not on dialysis. Neutralizing monoclonal antibodies may be an attractive option after a high-risk exposure or during the early course of infection.

Improved immunologic response to COVID-19 vaccine with prolonged dosing interval in haemodialysis patients

Vaccination against 2019 coronavirus disease (COVID-19) can reduce disease incidence and severity. Dialysis patients demonstrate a delayed immunologic response to vaccines. We determined factors affecting the immunologic response to COVID-19 vaccines in haemodialysis patients. All patients within a Swedish haemodialysis network, vaccinated with two doses of COVID-19 vaccine 2-8 weeks before inclusion, were eligible for this cross-sectional study. Severe adult respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein antibody levels were determined by EliA SARS-CoV-2-Sp1 IgG test (Thermo Fisher Scientific, Phadia AB) and related to clinical and demographic parameters. Eighty-nine patients were included. Patients were vaccinated with two doses of Comirnaty (BNT162b2, 73%) or Spikevax (mRNA-1273, 23,6%). Three patients received combinations of different vaccines. Response rate (antibody titres >7 U/mL) was 89.9%, while 39.3% developed high antibody titres (>204 U/mL), 47 (43-50) days after the second dose. A previous COVID-19 infection associated with higher antibody titres (median (25th-75th percentile) 1558.5 (814.5-3,763.8) U/mL vs 87 (26-268) U/mL, P = .002), while time between vaccine doses did not differ between groups (P = .7). Increasing SARS-CoV-2 antibody titres were independently associated with increasing time between vaccine doses (B 0.241, P = .02), decreasing serum calcium levels (B -0.233, P = .007) and previous COVID-19 (B 1.078, P < .001). In conclusion, a longer interval between COVID-19 mRNA vaccine doses, lower calcium and a previous COVID-19 infection were independently associated with a stronger immunologic vaccination response in haemodialysis patients. While the response rate was good, only a minority developed high antibody titres, 47 (43-50) days after the second vaccine dose.