Early Humoral Responses of Hemodialysis Patients after COVID-19 Vaccination with BNT162b2

Cellular and humoral response to SARS-CoV-2 vaccine BNT162b2 in adults with Chronic Kidney Disease G4/5

The mRNA vaccines have proven to be very effective in preventing severe disease and death from SARS-CoV-2 in the general population. However, in patients with chronic kidney disease (CKD) in dialysis or with kidney transplants (KT) the vaccine responses vary, with severe breakthrough infections as a consequence. In this intervention study we investigated the magnitude and quality of the responses to mRNA vaccination administered prior to kidney replacement therapy (KRT). Twenty patients with CKD G4/5 and nine healthy controls were followed for 12 months after receiving two doses of BNT162b2 four weeks apart and a booster dose after 3-6 months. Induction of anti-Spike and anti-RBD IgG in plasma followed the same kinetics in CKD patients and controls, with a trend towards higher titers in controls. In accordance, there was no differences in the establishment of Spike-specific memory B-cells between groups. In contrast, the CKD patients showed lower levels of anti-Spike IgG in saliva and Spike-specific CD8+ T-cells in blood, possibly influencing the capacity of viral clearance which can contribute to an elevated risk of severe breakthrough infections. In conclusion, we found that CKD patients, despite having a reduced mucosal and cytotoxic immunity to BNT162b2, demonstrated a serological response in plasma similar to healthy controls. This suggests that immunization prior to RRT is efficient and motivated. (EudraCT-nr 2021-000988-68).

Coronavirus disease 2019 vaccination effectiveness based on the 2021 Japanese dialysis registry

AIM

The effectiveness of the coronavirus disease (COVID-19) vaccine in Japanese patients undergoing haemodialysis has previously not been evaluated on a large scale. We analyzed data from the Japanese Society for Dialysis Therapy Renal Data Registry (JRDR), covering nearly all Japanese patients undergoing dialysis (~95% coverage), to examine the association between COVID-19 vaccination and infection or mortality.

METHODS

We used data from the JRDR end-of-year surveys conducted in 2020 and 2021, including information on the COVID-19 vaccination and infection months. COVID-19 infection incidence and its associated mortality rates based on vaccination status (time updated) and odds ratio (OR) (vaccinated vs. unvaccinated) were estimated monthly from April 2021, when vaccination commenced in Japan.

RESULTS

COVID-19 infection analysis included 228 865 patients (215 941 vaccinated and 12 924 unvaccinated patients at the end of 2021). The age- and sex-adjusted ORs (aORs) were significantly lower in August, September, October and November 2021, especially in September (aOR [95% confidence interval (CI)]: 0.25 [0.18-0.36]). Additional adjustments for past medical history and laboratory results rarely affected these results. Similarly, in the COVID-19-related mortality analysis with 228 731 patients, including 216 781 vaccinated and 11 950 unvaccinated at the end of 2021, COVID-19-related mortality risk was significantly lower in the vaccinated group in August, September, October and November (aOR [95% CI]: August, 0.32 [0.12-0.84], September, 0.04 [0.01-0.11]; October, 0.10 [0.01-0.81]; November, 0.05 [0.00-0.79]).

CONCLUSION

In Japanese patients undergoing haemodialysis, the first or second COVID-19 vaccine dose was significantly associated with decreased COVID-19 infection and mortality rates, suggesting its effectiveness in this population.

18-month longitudinal SARS COV-2 neutralizing antibody dynamics in haemodialysis patients receiving heterologous 3-dose vaccination (AZD-1222- AZD-1222- BNT162b2) in a lower middle income setting

BACKGROUND

Patients with chronic kidney disease on haemodialysis (HD) were given priority COVID-19 vaccination due to increased disease risk. The immune response to COVID-19 vaccination in patients on HD was diminished compared to healthy individuals in 2-dose studies. This study aimed to evaluate seroconversion rate, neutralizing antibody (nAB) levels and longitudinal antibody dynamics to 3-dose heterologous vaccination against COVID-19 in a cohort of HD patients compared to healthy controls and assess patient factors associated with antibody levels.

METHODS

This study was a case-control longitudinal evaluation of nAB dynamics in 74 HD patients compared to 37 healthy controls in a low/middle income setting. Corresponding samples were obtained from the two cohorts at time-points (TP) 1-1-month post 2nd dose of AZD1222 vaccine, TP2- 4 months post 2nd dose, TP4- 2 weeks post 3rd dose with BNT162b2 vaccine, TP5-5 months post 3rd dose and TP6-12 months post 3rd dose. Additional data is available at TP0- pre 2nd dose and TP3- 6 months post 2nd dose in HC and HD cohorts respectively. Anti-SARS-CoV-2 nAB were detected using Genscript cPassTM pseudoviral neutralization kit. Demographic and clinical details were obtained using an interviewer administered questionnaire.

RESULTS

Cohorts were gender matched while mean age of the HD cohort was 54.1yrs (vs HCs mean age, 42.6yrs, p < 0.05). Percentage seroconverted and mean/median antibody level (MAB) in the HD cohort vs HCs at each sampling point were, TP1-83.7% vs 100% (p < 0.05), MAB-450 IU/ml vs 1940 IU/ml (p < 0.0001); TP2-71.4% vs 100%, (p < 0.001), MAB- 235 IU/ml vs 453 IU/ml, (p < 0.05); TP4-95.2% vs 100% (p > 0.05), MAB-1029 IU/ml vs 1538 IU/ml (p < 0.0001); TP5-100% vs 100%, MAB-1542 IU/ml vs 1741IU/ml (p > 0.05); TP6-100% vs 100%, MAB-1961 IU/ml vs 2911 IU/ml (p > 0.05). At TP2, patients aged < 60 years (p < 0.001) were associated with maintaining seropositivity compared to patients > 60 years.

CONCLUSION

Two dose vaccination of haemodialysis patients provided poor nAB levels which improved markedly following 3rd dose vaccination, the effect of which was long- lasting with high nAB levels in both patients and controls detectable at 1 year follow-up.

Vaccination for Patients Receiving Dialysis

Vaccinating patients receiving dialysis may prevent morbidity and mortality in this vulnerable population. The National Forum of End-Stage Renal Disease Networks (the Forum) published a revised vaccination toolkit in 2021 to update evidence and recommendations on vaccination for patients receiving dialysis. Significant changes in the last 10 years include more data supporting the use of a high-dose influenza vaccine, the introduction of the Heplisav-B vaccine for hepatitis B, and changes in pneumococcal vaccines, including the approval of the PCV15 and PCV20 to replace the PCV13 and PPSV23 vaccines. Additional key items include the introduction of vaccines against severe acute respiratory syndrome coronavirus 2, the virus that causes coronavirus disease 2019 (COVID-19), and a new vaccine to prevent respiratory syncytial virus disease. Historically, influenza and pneumococcal vaccinations were routinely administered by dialysis facilities, and because of possible risks of hematogenous spread of hepatitis B, dialysis providers often have detailed hepatitis B vaccine protocols. In March 2021, COVID-19 vaccines were made available for dialysis facilities to administer, although with the end of the public health emergency, vaccine policies by dialysis facilities against COVID-19 remains uncertain. The respiratory syncytial virus vaccine was authorized in 2023, and how dialysis facilities will approach this vaccine also remains uncertain. This review summarizes the Forum's vaccination toolkit and discusses the role of the dialysis facility in vaccinating patients to reduce the risk of severe infections.

Potent induction of humoral and cellular immunity after bivalent BA.4/5 mRNA vaccination in dialysis patients

Knowledge on immunogenicity of the bivalent Omicron BA.4/5 vaccine in dialysis patients and the effect of a previous infection is limited. Therefore, vaccine-induced humoral and cellular immunity was analyzed in dialysis patients and immunocompetent controls with and without prior infection. In an observational study, 33 dialysis patients and 58 controls matched for age, sex and prior infection status were recruited. Specific IgG, neutralizing antibody activity and cellular immunity towards the spike-antigen from parental SARS-CoV-2 and Omicron-subvariants BA.1, BA.2 and BA.4/5 were analyzed before and 13-18 days after vaccination. The bivalent vaccine led to a significant induction of IgG, neutralizing titers, and specific CD4+ and CD8+ T-cell levels. Neutralizing activity towards the parental strain was higher than towards the Omicron-subvariants, whereas specific T-cell levels towards parental spike and Omicron-subvariants did not differ indicating substantial cross-reactivity. Dialysis patients with prior infection had significantly higher spike-specific CD4+ T-cell levels with lower CTLA-4 expression compared to infection-naive patients. When compared to controls, no differences were observed between infection-naive individuals. Among convalescent individuals, CD4+ T-cell levels were higher in patients and neutralizing antibodies were higher in controls. Vaccination was overall well tolerated in both dialysis patients and controls with significantly less adverse events among patients. In conclusion, our study did not provide any evidence for impaired immunogenicity of the bivalent Omicron BA.4/5 vaccine in dialysis patients. Unlike in controls, previous infection of patients was even associated with higher levels of spike-specific CD4+ T cells, which may reflect prolonged encounter with antigen during infection.

Live-virus serum neutralization after bivalent SARS-CoV-2 mRNA vaccination in hemodialysis patients

The development of bivalent booster vaccines addresses the ongoing evolution of the emerging B.1.1.529 (omicron) variant subtypes that are known to escape vaccine-induced neutralizing antibody response. Little is known about the immunogenicity and reactogenicity of bivalent mRNA vaccines in hemodialysis patients with impaired vaccine response. In this prospective, observational cohort study, we analyzed SARS-CoV-2 anti-S1 IgG, surrogate neutralizing antibodies (SNA), and live-virus neutralization against the SARS-CoV-2 wildtype and the BA.5 variant in 42 hemodialysis patients with and without prior SARS-CoV-2 infection before and after an additional fifth bivalent vaccine dose. Anti-S1 IgG and SNA were significantly higher in hemodialysis patients with prior infection than in patients without infection (p < 0.001 and p < 0.01, respectively). In patients without prior infection, both antibody levels increased, and live-virus neutralizing antibodies against the wildtype and the BA.5 variant were correspondingly significantly higher after bivalent booster vaccination (p < 0.001 for both). Conversely, in patients with prior infection, anti-S1 IgG and SNA did not alter significantly, and bivalent booster vaccination did not induce additional humoral immune response against the SARS-CoV-2 wildtype and the BA.5 variant. Thus, bivalent mRNA vaccines might increase humoral responses in hemodialysis patients without prior infection. Larger clinical trials are needed to help guide vaccination strategies in these immunocompromised individuals.

The prevention and treatment of COVID-19 in patients treated with hemodialysis

Patients treated with hemodialysis are often immunocompromised due to concomitant disease. As a result, this population is at high risk of infection and mortality from COVID-19. In addition to symptomatic treatment, a series of antiviral drugs targeting COVID-19 are now emerging. However, these antivirals are used mainly in mild or moderate patients with high-risk factors for progression to severe disease and are not available as pre- or post-exposure prophylaxis for COVID-19. There is a lack of clinical data on the use of anti-COVID-19 drugs, especially in patients treated with hemodialysis, therefore, vaccination remains the main measure to prevent SARS-CoV-2 infection in these patients. Here, we review the clinical features and prognosis of patients on hemodialysis infected with SARS-CoV-2, the main anti-COVID-19 drugs currently available for clinical use, and the safety and efficacy of anti-COVID-19 drugs or COVID-19 vaccination in patients treated with hemodialysis. This information will provide a reference for the treatment and vaccination of COVID-19 in patients treated with hemodialysis and maximize the health benefits of these patients during the outbreak.

Assessment of humoral immune response to different COVID-19 vaccines in patients undergoing maintenance hemodialysis

INTRODUCTION

The immune response to different Coronavirus Disease 2019 (COVID-19) vaccines is under-investigated in end-stage kidney disease (ESKD) patients, especially in the Middle East and North Africa. We carried out this research to estimate the effectiveness of COVID-19 immunization in ESKD patients on regular hemodialysis (HD).

METHODS

In this prospective observational study, we enrolled 60 ESKD patients on regular HD who had completed COVID-19 vaccination and 30 vaccinated healthy participants. Serum levels of severe acute respiratory syndrome coronavirus 2 immunoglobulin G (SARS-COV2 IgG) were quantified 1 month after completing the vaccination schedule, and all participants were followed up from October 2021 to March 2022. The vaccines used in the study were from Pfizer-BioNTech, AstraZeneca, and Sinopharm.

RESULTS

The median level of SARS-COV2 IgG was lower in HD patients than in healthy participants (p < 0.001). Regarding the type of COVID-19 vaccination, there was no statistical difference in SARS-COV2 IgG levels among HD patients. During the observation period, none of the HD patients had COVID-19.

CONCLUSION

COVID-19 vaccination appeared to be protective in HD patients for 6 months and the side effects of vaccines were tolerable.

COVID-19 Vaccination Among Patients Receiving Maintenance Renal Replacement Therapy: Immune Response, Real-World Effectiveness, and Implications for the Future

Chronic kidney disease affects more than 800 million people worldwide and often progresses to end-stage renal disease, which requires maintenance dialysis. Patients receiving dialysis are at higher risk for severe respiratory infections, including SARS-CoV-2 (the causative agent of COVID-19). In addition, many patients who receive dialysis also receive immunosuppressive treatments for conditions such as systemic vasculitis, systemic lupus erythematosus, or malignancies. Many studies have shown that while mRNA COVID-19 vaccines induce some level of immune response in patients receiving dialysis, the magnitude of response is often lower than that of healthy individuals, and responses rapidly wane. Importantly, the risk of COVID-19-related hospitalization and mortality for patients receiving dialysis is 4- to 8-fold higher compared with the general population. In this article, we summarize recent immunogenicity and real-world outcomes of COVID-19 mRNA vaccination among patients receiving dialysis, with a focus on the 3-dose extended primary series and additional (fourth) doses.

COVID-19 vaccination effectiveness and safety in vulnerable populations: a meta-analysis of 33 observational studies

Background: Even 3 years into the COVID-19 pandemic, questions remain about how to safely and effectively vaccinate vulnerable populations. A systematic analysis of the safety and efficacy of the COVID-19 vaccine in at-risk groups has not been conducted to date. Methods: This study involved a comprehensive search of PubMed, EMBASE, and Cochrane Central Controlled Trial Registry data through 12 July 2022. Post-vaccination outcomes included the number of humoral and cellular immune responders in vulnerable and healthy populations, antibody levels in humoral immune responders, and adverse events. Results: A total of 23 articles assessing 32 studies, were included. The levels of IgG (SMD = -1.82, 95% CI [-2.28, -1.35]), IgA (SMD = -0.37, 95% CI [-0.70, -0.03]), IgM (SMD = -0.94, 95% CI [-1.38, -0.51]), neutralizing antibodies (SMD = -1.37, 95% CI [-2.62, -0.11]), and T cells (SMD = -1.98, 95% CI [-3.44, -0.53]) were significantly lower in vulnerable than in healthy populations. The positive detection rates of IgG (OR = 0.05, 95% CI [0.02, 0.14]) and IgA (OR = 0.03, 95% CI [0.01, 0.11]) antibodies and the cellular immune response rates (OR = 0.20, 95% CI [0.09, 0.45]) were also lower in the vulnerable populations. There were no statistically significant differences in fever (OR = 2.53, 95% CI [0.11, 60.86]), chills (OR = 2.03, 95% CI [0.08, 53.85]), myalgia (OR = 10.31, 95% CI [0.56, 191.08]), local pain at the injection site (OR = 17.83, 95% CI [0.32, 989.06]), headache (OR = 53.57, 95% CI [3.21, 892.79]), tenderness (OR = 2.68, 95% CI [0.49, 14.73]), and fatigue (OR = 22.89, 95% CI [0.45, 1164.22]) between the vulnerable and healthy populations. Conclusion: Seroconversion rates after COVID-19 vaccination were generally worse in the vulnerable than healthy populations, but there was no difference in adverse events. Patients with hematological cancers had the lowest IgG antibody levels of all the vulnerable populations, so closer attention to these patients is recommended. Subjects who received the combined vaccine had higher antibody levels than those who received the single vaccine.

Immune response of heterologous versus homologous prime-boost regimens with adenoviral vectored and mRNA COVID-19 vaccines in immunocompromised patients

Due to rare but major adverse reactions to the AstraZeneca adenoviral ChAdOx1-S-nCoV-19 vaccine (ChAd), German health authorities recommended adults under 60 who received one dose of ChAd, to receive a second dose of the BioNTech mRNA BNT162b2 vaccine (BNT) as a booster. Studies in the general population suggest an enhanced efficacy of the heterologous (ChAd-BNT) compared to the homologous (BNT-BNT) vaccination regimen. However, an analysis of the efficacy in patient populations with a high risk of severe COVID-19 due to acquired immunodeficiency is still missing. We therefore compared both vaccination regimens in healthy controls, patients with gynecological tumors after chemotherapy, patients on dialysis and patients with rheumatic diseases concerning the humoral and cellular immune response. The humoral and cellular immune response differed substantially in healthy controls compared to patients with acquired immunodeficiency. Overall, the most significant differences between the two immunization regimens were found in neutralizing antibodies. These were always higher after a heterologous immunization. Healthy controls responded well to both vaccination regimens. However, the formation of neutralizing antibodies was more pronounced after a heterologous immunization. Dialysis patients, on the other hand, only developed an adequate humoral and particularly cellular immune response after a heterologous immunization. Tumor and rheumatic patients also - to a weaker extent compared to dialysis patients - benefited from a heterologous immunization. In conclusion, the heterologous COVID-19 vaccination regimens (ChAd-BNT) seem to have an advantage over the homologous vaccination regimens, especially in immunocompromised patients such as patients with end-stage kidney disease treated with hemodialysis.

The challenges of the pandemic and the vaccination against covid-19 in pediatric patients with kidney disease

The covid-19 vaccine confers direct protection and reduces transmission rates of the virus and new variants. Vaccines from Pfizer/BioNTech and CoronaVac have been cleared for children in Brazil. They are safe, effective, and immunogenic. There are no known complications associated with the use of steroids or vaccines in pediatric patients with covid-19 and nephrotic syndrome. With or without immunosuppression, these patients are not at increased risk of severe covid-19, and steroids are safe for them. A milder form of covid-19 occurs in patients with chronic kidney disease without the need for hospitalization. The vaccine response may be reduced and/or the duration of antibodies after vaccination may be shorter than in the general population. However, considering risk of exposure, vaccination against covid-19 is recommended. It is believed that patients with hemolytic-uremic syndrome are at higher risk of severe covid-19. Vaccination is recommended, although specific data on the safety and efficacy of the covid-19 vaccine are limited. There is agreement that the benefits of induced immunity outweigh the risks of immunization. Vaccination against covid-19 is recommended for children and adolescents needing kidney transplantation or who have undergone transplantation. These patients present decreased immune response after vaccination, but immunization is recommended because the benefits outweigh the risks of vaccination. Current recommendations in Brazil stipulate the use of the messenger RNA vaccine. This paper aims to provide pediatric nephrologists with the latest knowledge about vaccination against covid-19 for children with kidney disease.

Outcomes of vaccinations against respiratory diseases in patients with end-stage renal disease undergoing hemodialysis: A systematic review and meta-analysis

Due to the nature of the disease, end-stage renal disease (ESRD) patients suffer from dysfunction of the adaptive immune system, which leads to a poorer response to vaccination. Accordingly, it is crucial to evaluate the efficacy and safety of management strategies, including vaccinations, which could potentially reduce the risk of respiratory diseases, such as pneumonia, influenza, or COVID-19, and its associated outcomes. We searched PubMed, CENTRAL, ScienceDirect, Scopus, ProQuest, and Google Scholar databases using designated MeSH keywords. The risk of bias was assessed using ROBINS-I. The quality of evidence was assessed using the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) approach. Relative risk (RR) and 95% confidence interval (CI) were calculated. Heterogeneity was investigated using forest plots and I2 statistics. This systematic review included a total of 48 studies, with 13 studies of influenza (H1N1 and H3N2) vaccination and 35 studies of COVID-19 vaccination. H1N1 vaccination in ESRD patients undergoing hemodialysis induced lower seroconversion rates (RR 0.62, 95% CI: 0.56-0.68, p <0.00001) and lower seroprotection rates (RR 0.76, 95% CI: 0.70-0.83, p <0.00001) compared to controls. H3N2 vaccination in ESRD patients undergoing hemodialysis yielded lower seroconversion rates (RR 0.76, 95% CI: 0.68-0.85, p <0.00001) and lower seroprotection rates (RR 0.84, 95% CI: 0.77-0.90, p <0.00001) compared to controls. Twenty-nine studies demonstrate significantly lower antibody levels in ESRD patients undergoing hemodialysis compared to the controls following COVID-19 vaccination. This review presents evidence of lower seroconversion and seroprotection rates after vaccination against viral respiratory diseases in patients with ESRD undergoing hemodialysis. Since hemodialysis patients are more susceptible to infection and severe disease progression, a weakened yet substantial serological response can be considered adequate to recommend vaccination against respiratory diseases in this population. Vaccination dose, schedule, or strategy adjustments should be considered in stable ESRD patients on maintenance hemodialysis. Trial registration: Systematic review registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021255983, identifier: CRD42021255983.

Waning Humoral Response 6 Month after Double Vaccination with the mRNA-BNT162b2 Vaccine in Hemodialysis Patients

Introduction

Although most hemodialysis patients (HDP) exhibit an initial seroresponse to vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), studies have shown this response to be lower compared to healthy subjects. This fact raised concerns regarding the durability of the immune response and effective protection against severe Coronavirus disease 2019 (COVID-19) in this vulnerable population. The aim of our study was to evaluate the change in antibody levels over time in HDP population.

Materials and Methods

We performed a prospective multicenter study, evaluating antibody response among HDP at 2 and at 6 months after complete two-dose vaccination course with the mRNA-BNT162b2 (Pfizer-BioNTech) vaccine. The study was performed in 14 hemodialysis units of a private dialysis provider in Lithuania. The serum samples of 189 HDP were tested for SARS-CoV-2 IgG against the Spike glycoprotein.

Results

189 HDP participated in the study. Patients were 64.3±15.7 years of age, 116 (61.4%) were males and 73 (38.6%) were females. Among them, 183 (96.8%) were seropositive for anti-S IgG at 2 months after the second immunization dose. Six months after the second dose only 145 (76.7%) of study participants had positive anti-S IgG titers. The median level of anti-S IgG titers after 2 months was 383.1 BAU/mL (166.2-995.6) and after 6 months this level significantly decreased to 51.4 BAU/mL (22.0-104.0) (p<0.001). Seroresponses at both time points inversely correlated with increasing patient's age. Risk factor for absent response after 2 months included oncologic disease. Systemic autoimmune disease and a history of myocardial infarction increased risk to be seronegative 6 months after the second vaccine dose.

Conclusions

The majority of hemodialysis patients seroresponded after BNT162b2/Pfizer vaccination, but vaccine-induced humoral immunity wanes over time.

Ultrasensitive monitoring of SARS-CoV-2-specific antibody responses based on a digital approach reveals one week of IgG seroconversion

COVID-19 is still unfolding, while many people have been vaccinated. In comparison to nucleic acid testing (NAT), antibody-based immunoassays are faster and more convenient. However, its application has been hampered by its lower sensitivity and the existing fact that by traditional immunoassays, the measurable seroconversion time of pathogen-specific antibodies, such as IgM or IgG, lags far behind that of nucleic acids. Herein, by combining the single molecule array platform (Simoa), RBD, and a previously identified SARS-CoV-2 S2 protein derivatized 12-aa peptide (S2-78), we developed and optimized an ultrasensitive assay (UIM-COVID-19 assay). Sera collected from three sources were tested, i.e., convalescents, inactivated virus vaccine-immunized donors and wild-type authentic SARS-CoV-2-infected rhesus monkeys. The sensitivities of UIM-COVID-19 assays are 100-10,000 times higher than those of conventional flow cytometry, which is a relatively sensitive detection method at present. For the established UIM-COVID-19 assay using RBD as a probe, the IgG and IgM seroconversion times after vaccination were 7.5 and 8.6 days vs. 21.4 and 24 days for the flow cytometry assay, respectively. In addition, using S2-78 as a probe, the UIM-COVID-19 assay could differentiate COVID-19 patients (convalescents) from healthy people and patients with other diseases, with AUCs ranging from 0.85-0.95. In summary, the UIM-COVID-19 we developed here is a promising ultrasensitive biodetection strategy that has the potential to be applied for both immunological studies and diagnostics.

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.

A systematic review assessing the effectiveness of COVID-19 mRNA vaccines in chronic kidney disease (CKD) individuals

Background: SARS-CoV-2 is a coronavirus that has rapidly spread across the world with a detrimental effect on the global population. Several reports have highlighted an increased mortality rate and a higher severity of COVID-19 infection in chronic kidney disease (CKD) individuals. Upon the development of various SARS-CoV-2 vaccines, mRNA vaccines including BNT162b2 and mRNA-1273 were deemed safe, with a high efficacy in preventing COVID-19 in the general population. This review investigates whether  SARS-CoV-2 mRNA vaccines are as effective in triggering an immune response in Dialysis Patients (DPs) and Kidney Transplant Recipients (KTRs) and if a third dose is required in this  population. Methods: A systematic search employing the PRISMA criteria was conducted in several major databases, with the data being extracted from publications for the period January 2021 to May 2022 (PROSPERO: CRD42022338514, June 15, 2022). Results: 80 studies were included in this analysis with a total cohort number of 15,059 participants. Overall, 85.29% (OR = 17.08, 95% CI = 15.84-18.42, I ² = 98%) and 41.06% (OR = 0.52, 95% CI = 0.48-0.5, I ² = 95%) of DPs and KTRs included in this review showed positive seroconversion after two doses of either mRNA vaccine, respectively. A total 76% (OR = 6.53, 95% CI = 5.63-7.5, I ² = 96%) of the cohort given a third dose of an mRNA vaccine demonstrated positive seroconversion, with 61.86% (OR = 2.31, 95% CI = 1.95-2.75 I ² = 95%) of the cohort that was assessed for a cellular response displaying a positive response. Conclusions: This data emphasises a reduced incidence of a positive immune response in DPs and KTRs compared to healthy controls, albeit a better response in DPs than when compared to KTRs alone was observed. A third dose  appears to increase the occurrence of an immune response in the overall DP/KTR cohort.

Effectiveness of COVID-19 vaccines in a large European hemodialysis cohort

Background

Hemodialysis patients have high-risk of severe SARS-CoV-2 infection but were unrepresented in randomized controlled trials evaluating the safety and efficacy of COVID-19 vaccines. We estimated the real-world effectiveness of COVID-19 vaccines in a large international cohort of hemodialysis patients.

Methods

In this historical, 1:1 matched cohort study, we included adult hemodialysis patients receiving treatment from December 1, 2020, to May 31, 2021. For each vaccinated patient, an unvaccinated control was selected among patients registered in the same country and attending a dialysis session around the first vaccination date. Matching was based on demographics, clinical characteristics, past COVID-19 infections and a risk score representing the local background risk of infection at vaccination dates. We estimated the effectiveness of mRNA and viral-carrier COVID-19 vaccines in preventing infection and mortality rates from a time-dependent Cox regression stratified by country.

Results

In the effectiveness analysis concerning mRNA vaccines, we observed 850 SARS-CoV-2 infections and 201 COVID-19 related deaths among the 28110 patients during a mean follow up of 44 ± 40 days. In the effectiveness analysis concerning viral-carrier vaccines, we observed 297 SARS-CoV-2 infections and 64 COVID-19 related deaths among 12888 patients during a mean follow up of 48 ± 32 days. We observed 18.5/100-patient-year and 8.5/100-patient-year fewer infections and 5.4/100-patient-year and 5.2/100-patient-year fewer COVID-19 related deaths among patients vaccinated with mRNA and viral-carrier vaccines respectively, compared to matched unvaccinated controls. Estimated vaccine effectiveness at days 15, 30, 60 and 90 after the first dose of a mRNA vaccine was: for infection, 41.3%, 54.5%, 72.6% and 83.5% and, for death, 33.1%, 55.4%, 80.1% and 91.2%. Estimated vaccine effectiveness after the first dose of a viral-carrier vaccine was: for infection, 38.3% without increasing over time and, for death, 56.6%, 75.3%, 92.0% and 97.4%.

Conclusion

In this large, real-world cohort of hemodialyzed patients, mRNA and viral-carrier COVID-19 vaccines were associated with reduced COVID-19 related mortality. Additionally, we observed a strong reduction of SARS-CoV-2 infection in hemodialysis patients receiving mRNA vaccines.

Immunogenicity of COVID-19 mRNA vaccines in hemodialysis patients: Systematic review and meta-analysis

Background and Aims

Vaccine response is a concern in hemodialysis patients. Given that hemodialysis patients were not included in clinical trials, we aimed to synthesize the available evidence on the immunogenicity of coronavirus disease 2019 (COVID-19) mRNA vaccines in hemodialysis patients.

Methods

We searched Scopus, PubMed, Sciencedirect, and finally google scholar databases for studies on COVID-19 mRNA-vaccines immunogenicity in hemodialysis patients up to December 1, 2021. Eligible articles measured antibodies against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike or Receptor-Binding Domain Antibody (S/RBD) postimmunization with COVID-19 mRNA vaccines. The immunogenicity of the vaccine was evaluated using seroconversion rates measured between 21 and 30 days after the first immunization and between 14 and 36 days post the second dose. We included studies including participants without a history of COVID-19 before vaccination. Healthy controls or health-care workers served as the control groups. After selecting eligible articles, the data were finally extracted from included articles. We used a random effects model to estimate the pooled seroconversion rate after COVID-19 mRNA vaccine administration. We assessed the heterogeneity between studies with the I 2 statistical index.

Result

We selected 39 eligible citations comprising 806 cases and 336 controls for the first dose and 6314 cases and 927 controls for the second dose for statistical analysis. After the first dose of mRNA vaccines, the seroconversion rate was 36% (95% confidence interval [CI]: 0.24-0.47) and 68% (95% CI: 0.45-0.91) in hemodialysis patients and the control group, respectively. While seroconversion rate after the second dose of mRNA vaccines was 86% (95% CI: 0.81-0.91) and 100% (95% CI: 1.00-1.00) in hemodialysis patients and the control group, respectively.

Conclusion

Although the immune response of hemodialysis patients to the second dose of the SARS-CoV-2 mRNA vaccine is very promising, the seroconversion rate of dialysis patients is lower than healthy controls. Periodically assessment of antibody levels of hemodialysis patients at short intervals is recommended.

Os desafios da pandemia e a vacinação covid-19 na população pediátrica com doenças renais

Resumo A vacina covid-19 confere proteção direta, reduz as taxas de transmissão do vírus e de novas variantes. No Brasil, estão liberadas para a população pediátrica as vacinas Pfizer/BioNTech e a CoronaVac, ambas seguras, eficazes e imunogênicas. Pacientes pediátricos com síndrome nefrótica e covid-19 têm curso clínico regular sem complicações relacionadas ao uso de esteroides ou vacinas. Esses pacientes, com ou sem imunossupressão, não apresentam maior risco de covid-19 grave e o tratamento com esteroides é seguro. Os pacientes com doença renal crônica têm covid-19 mais leve, sem necessidade de hospitalização. A resposta vacinal pode ser reduzida e/ou a duração dos anticorpos pós-vacinação pode ser menor do que na população geral. Entretanto, a vacina covid-19 está recomendada, considerando o risco de exposição. Acredita-se que pacientes com síndrome hemolítico-urêmica teriam maior risco de covid-19 grave. A vacina é recomendada, embora dados específicos sobre segurança e eficácia da vacina covid-19 sejam limitados. Há concordância que os benefícios da imunidade induzida superam quaisquer riscos da imunização. A vacina covid-19 é recomendada para crianças e adolescentes candidatos ao transplante renal ou já transplantados. Esses pacientes têm resposta imunológica reduzida após a vacina, entretanto ela é recomendada porque os benefícios superam qualquer risco dessa vacinação. A recomendação atual no Brasil é a vacina de tecnologia RNA mensageiro. O objetivo deste documento é levar aos nefrologistas pediátricos os conhecimentos mais recentes sobre a vacinação contra contra-19 em crianças com doenças renais.

Humoral Response to Hepatitis B and COVID-19 Vaccine among Maintenance Hemodialysis Patients

Maintenance hemodialysis (MHD) patients have impaired immunological responses to pathogens and vaccines. In this study, we compared the humoral response to HBV and COVID-19 vaccines in a cohort of MHD patients. Demographic and clinical characteristics of vaccine responders and non-responders were also compared, and the association between the humoral responses to both vaccines was evaluated. The cohort included 94 MHD patients who were vaccinated at least once for HBV and twice for COVID-19. Among the 94 patients, 28 (29.8%) did not develop protective titers to HBV. Hypertension, coronary heart disease, and heart failure were more common in non-responders. Among MHD patients, 85% had positive IgG anti-spike SARS-CoV-2 levels 6 months after two doses of BNT162b2 (Pfizer/Biotech) vaccine. Age and immunosuppressive therapy were the main predictors of humoral response to COVID-19 vaccine. We did not find any association between non-responders to HBV and non-responders to COVID-19 vaccine. There was no difference in IgG anti-spike titers between HBV responders and non-responders (505 ± 644 vs. 504 ± 781, p = 0.9) Our results suggest that reduced humoral response to hepatitis B is not associated with reduced response to COVID-19 vaccine. Different risk-factors were associated with poor immune response to HBV and to COVID-19 vaccines.

Immunogenicity and safety of SARS-CoV-2 vaccine in hemodialysis patients: A systematic review and meta-analysis

Rationale and objective

COVID-19 vaccination is the most effective way to prevent COVID-19. For chronic kidney disease patients on long-term dialysis, there is a lack of evidence on the pros and cons of COVID-19 vaccination. This study was conducted to investigate the immunogenicity and safety of COVID-19 vaccines in patients on dialysis.

Methods

PubMed, MEDLINE, EMBASE, and the Cochrane Library were systemically searched for cohort, randomized controlled trials (RCTs), and cross-sectional studies. Data on immunogenicity rate, antibody titer, survival rate, new infection rate, adverse events, type of vaccine, and patient characteristics such as age, sex, dialysis vintage, immunosuppression rate, and prevalence of diabetes were extracted and analyzed using REVMAN 5.4 and Stata software. A random effects meta-analysis was used to perform the study.

Results

We screened 191 records and included 38 studies regarding 5,628 participants. The overall immunogenicity of dialysis patients was 87% (95% CI, 84-89%). The vaccine response rate was 85.1 in hemodialysis patients (HDPs) (1,201 of 1,412) and 97.4% in healthy controls (862 of 885). The serological positivity rate was 82.9% (777 of 937) in infection-naive individuals and 98.4% (570 of 579) in patients with previous infection. The Standard Mean Difference (SMD) of antibody titers in dialysis patients with or without previous COVID-19 infection was 1.14 (95% CI, 0.68-1.61). Subgroup analysis showed that the immunosuppression rate was an influential factor affecting the immunogenicity rate (P < 0.0001). Nine studies reported safety indices, among which four local adverse events and seven system adverse events were documented.

Conclusions

Vaccination helped dialysis patients achieve effective humoral immunity, with an overall immune efficiency of 87.5%. Dialysis patients may experience various adverse events after vaccination; however, the incidence of malignant events is very low, and no reports of death or acute renal failure after vaccination are available, indicating that vaccine regimens may be necessary.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/display_record.asp?ID=CRD42022342565, identifier: CRD42022342565.

Antibody Response and Adverse Events of AZD1222 COVID-19 Vaccination in Patients Undergoing Dialysis: A Prospective Cohort Study

This study observed the antibody response and adverse events of AZD1222 (Oxford/AstraZeneca) vaccination in dialysis patients. A prospective cohort study was conducted in E-Da Healthcare Group hospitals between 1 July and 30 November 2021. Patients receiving hemodialysis (HD, n = 204) or peritoneal dialysis (PD, n = 116) were enrolled alongside healthy subjects (control, n = 34). Anti-SARS-CoV-2 S1 RBD IgG antibodies were measured before the first vaccination (T0), four to six weeks afterwards (T1), one week before the second dose (T2), and four to six weeks afterwards (T3). Adverse events were recorded one week after each dose. The positive IgG rates in the HD (T1: 72%; T2: 62%) and PD (T1: 69%; T2: 70%) groups were lower than the control group (T1: 97%; T2: 91%), with lower median antibody titers. At T3, the positive antibody response rates (HD: 94%; PD: 93%; control: 100%) and titers were similar. Titers were higher after the second dose in all groups. Adverse events were more severe after the first dose and less common with HD than PD or controls. Dialysis patients exhibited lower antibody responses than controls after the first dose of the AZD1222 vaccine but achieved similar responses after consecutive vaccination. Age, health status, two vaccine doses, and alcohol consumption may influence antibody levels.

Efficacy and Safety of COVID-19 Vaccine in Patients on Renal Replacement Therapy

Patients with CKD on RRT are at high risk for severe disease and mortality in COVID-19 disease. We decided to conduct an observational prospective study to evaluate antibody response after vaccination for COVID-19 in a cohort of 210 adult patients on RRT (148 on HD; 20 on PD; and 42 kidney transplant recipients). Blood samples were taken before and 4 weeks after vaccination. Antibody levels were evaluated with CLIA immunoassay testing for IgG anti-trimeric spike protein of SARS-CoV-2. A positive antibody titer was present in 89.9% of HD patients, 90% of PD patients, and 52.4% of kidney transplant recipients. Non-responders were more frequent among patients on immunosuppressive therapy. Mycophenolate use in kidney transplant patients was associated with lower antibody response. The median antibody titer was 626 (228–1480) BAU/mL; higher in younger patients and those previously exposed to the virus and lower in HD patients with neoplasms and/or on immunosuppressive therapy. Only two patients developed COVID-19 in the observation period: they both had mild disease and antibody titers lower than 1000 BAU/mL. Our data show a valid response to COVID-19 mRNA vaccination in HD and PD patients and a reduced response in kidney transplant recipients. Mycophenolate was the most relevant factor associated with low response.

Indoxyl Sulfate Alters the Humoral Response of the ChAdOx1 COVID-19 Vaccine in Hemodialysis Patients

Background and aims: Vaccination for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) is strongly recommended. The efficacy of SARS-CoV-2 vaccine for patients with end-stage renal disease is low. Indoxyl sulfate (IS) is a representative protein bound uremic toxin arousing immune dysfunction in CKD patients. It is unknown whether IS impairs the efficacy of vaccines for SARS-CoV-2. Materials and Methods: From 1 June 2021, to 31 December 2021, hemodialysis patients (n = 358) and a control group (n = 59) were eligible to receive the first dose of the ChAdOx1 COVID-19 vaccine. Titer measurements indicative of the humoral response (anti-S1 IgG and surrogate virus neutralization test (sVNT) results) and indoxyl sulfate concentration measurement were performed 4 weeks after ChAdOx1 vaccine injection. Results: The serum concentrations of anti-S1 IgG were 272 ± 1726 AU/mL and 2111 ± 4424 AU/mL in hemodialysis patients and control group (p < 0.05), respectively. The sVNT values were 26.8 ± 21.1% and 54.0 ± 20.2% in the hemodialysis and control groups (p < 0.05), respectively. There was a decreasing trend for the anti-S1 IgG titer from the lowest to highest quartile of IS (p < 0.001). The patients with higher concentrations of IS had lower sVNT (p for trend < 0.001). Conclusion: Hemodialysis patients had weaker humoral immunity after the first dose of the ChAdOx1 vaccine. Higher concentration of IS altered the development of anti-S1 antibodies and sVNT-measured neutralization.

Investigation for the efficacy of COVID-19 vaccine in Japanese CKD patients treated with hemodialysis

Background

Dialysis patients are predisposed to severe disease and have a high mortality rate in coronavirus disease 2019 (COVID-19) due to their comorbidities and immunocompromised conditions. Therefore, dialysis patients should be prioritized for vaccination. This study aimed to examine how long the effects of the vaccine are maintained and what factors affect antibody titers.

Methods

Hemodialysis patients (HD group) and age- and sex-matched non-dialysis individuals (Control group), receiving two doses of BNT162b2 vaccine, were recruited through the Japanese Society for Dialysis Therapy (JSDT) Web site in July 2021. Anti-SARS-CoV-2 immunoglobulin (IgG) (SARS-CoV-2 IgG titers) was measured before vaccination, 3 weeks after the first vaccination, 2 weeks after the second vaccination, and 3 months after the second vaccination, and was compared between Control group and HD group. Factors affecting SARS-CoV-2 IgG titers were also examined using multivariable regression analysis and stepwise regression analysis (least AIC). In addition, we compared adverse reactions in Control and HD groups and examined the relationship between adverse reactions and SARS-CoV-2 IgG titers.

Results

Our study enrolled 123 participants in the Control group (62.6% men, median age 67.0 years) and 206 patients in the HD group (64.1% men, median age 66.4 years). HD group had significantly lower SARS-CoV-2 IgG titers at 3 weeks after the first vaccination (p < 0.0001), 2 weeks after second vaccination (p = 0.0002), and 3 months after the second vaccination (p = 0.045) than Control group. However, the reduction rate of SARS-CoV-2 IgG titers between 2 weeks and 3 months after the second vaccination was significantly smaller in HD group than in Control (p = 0.048). Stepwise regression analysis revealed that dialysis time was identified as the significant independent factors for SARS-CoV-2 IgG titers at 2 weeks after the second vaccination in HD group (p = 0.002) and longer dialysis time resulted in higher maximum antibody titers. The incidences of fever and nausea after the second vaccination were significantly higher in the HD group (p = 0.039 and p = 0.020). Antibody titers in those with fever were significantly higher than those without fever in both groups (HD: p = 0.0383, Control: p = 0.0096).

Conclusion

HD patients had significantly lower antibody titers than age- and sex-matched non-dialysis individuals over 3 months after vaccination. Dialysis time was identified as a factor affecting SARS-CoV-2 IgG titers in HD group, with longer dialysis time resulting in higher maximum SARS-CoV-2 IgG titers.

Humoral response to SARS-CoV-2 mRNA vaccination in previous non-responder kidney transplant recipients after short-term withdrawal of mycophenolic acid

Seroconversion rates after COVID-19 vaccination are significantly lower in kidney transplant recipients compared to healthy cohorts. Adaptive immunization strategies are needed to protect these patients from COVID-19. In this prospective observational cohort study, we enrolled 76 kidney transplant recipients with no seroresponse after at least three COVID-19 vaccinations to receive an additional mRNA-1273 vaccination (full dose, 100 μg). Mycophenolic acid was withdrawn in 43 selected patients 5–7 days prior to vaccination and remained paused for 4 additional weeks after vaccination. SARS-CoV-2-specific antibodies and neutralization of the delta and omicron variants were determined using a live-virus assay 4 weeks after vaccination. In patients with temporary mycophenolic acid withdrawal, donor-specific anti-HLA antibodies and donor-derived cell-free DNA were monitored before withdrawal and at follow-up. SARS-CoV-2 specific antibodies significantly increased in kidney transplant recipients after additional COVID-19 vaccination. The effect was most pronounced in individuals in whom mycophenolic acid was withdrawn during vaccination. Higher SARS-CoV-2 specific antibody titers were associated with better neutralization of SARS-CoV-2 delta and omicron variants. In patients with short-term withdrawal of mycophenolic acid, graft function and donor-derived cell-free DNA remained stable. No acute rejection episode occurred during short-term follow-up. However, resurgence of prior anti-HLA donor-specific antibodies was detected in 7 patients.

Vaccination against SARS-CoV-2 in Haemodialysis Patients: Spike's Ab Response and the Influence of BMI and Age

Patients with chronic kidney disease (CKD-5D) in dialysis have been associated with higher rates of SARS-CoV-2 infection. Objective: To identify the CKD-5D patients’ immune system behavior regarding the Pfizer-BioNTech (BNT162b2 mRNA) vaccine (Comirnaty©). This was a multicenter study carried out in 38 dialysis units in NephroCare Portugal. Eligible patients from two cohorts—one composed of completely vaccinated patients with Comirnaty© (vaccinated group) against a second cohort of patients who recovered from SARS-CoV-2 infection (control group)—were selected through representative sampling for each cohort. Humoral response was assessed at 3 (t0) and 6 months (t1) after complete vaccination and, in the control group, 6 months after COVID-19 recovery. In the vaccinated group, at t0, the median anti-Spike IgG level was 1120 AU/mL and, at t1, all participants’ antibody level decreased to a median of 455 AU/mL. In the control group, the median serum SARS-CoV-2 antibodies level was 1836 AU/mL. In the vaccinated group, at t0, patients < 70 years presented a significantly (p = 0.002) higher level of anti-Spike IgG titres. In contrast, older patients from the control group presented a significantly (p = 0.038) higher IgG. No correlation was found between age and anti-Spike IgG antibodies level in any of the studied groups. Patients with a higher body mass index showed a greater immune response in both the vaccinated and control group, although without significance. We concluded that, in the vaccinated group, elderly patients developed a lower immune response than younger patients and the levels of anti-Spike IgG antibodies declined faster between t0 and t1, while in the control group, the oldest and overweight patients developed the best humoral response.

Antibody responses to the SARS-CoV-2 vaccines in hemodialysis patients: Is inactivated vaccine effective?

INTRODUCTION

Vaccines generally have reduced effectiveness in hemodialysis patients and a similar condition may also apply for the SARS-CoV-2 vaccines. The aim of this study was to analyze humoral responses of hemodialysis patients to SARS-CoV-2 vaccines.

METHODS

Eighty-five maintenance hemodialysis patients who received either inactivated or mRNA SARS-CoV-2 vaccines were investigated. Antibody levels were measured by a commercial antibody kit, which detected antibodies toward receptor binding domain of the SARS-CoV-2 spike protein. Comparative analyzes were carried between vaccine groups and with a control group of 103 healthy volunteers.

RESULTS

Seropositivity rate and antibody levels were significantly lower in hemodialysis patients who received inactivated vaccine (p = 0.000). While mRNA vaccine had better immunogenicity, both vaccines protected from symptomatic infection when seropositivity was achieved.

DISCUSSION/CONCLUSION

When used in the same dose with the general population, inactivated SARS-CoV-2 vaccines generate reduced humoral response in hemodialysis patients. mRNA vaccines have better immunogenicity in this group.

Impact of Variant of Concern and Vaccination Status on COVID-19 Infection Virological Dynamics in End Stage Kidney Disease Patients Receiving Haemodialysis

BACKGROUND

It is unclear if variant of concern and vaccination status impact COVID-19 infection virological dynamics in haemodialysis patients and affect de-isolation protocol for dialysis centres.

METHOD

We performed a retrospective observational cohort study between February 2020 to September 2021, to examine the virological kinetics of vaccinated and unvaccinated haemodialysis patients with polymerase chain reaction (PCR)-confirmed COVID-19 infection of the delta and pre-delta variants.

RESULTS

Of the 38 subjects with PCR-confirmed COVID-19 infection, we found that individuals infected during the delta-variant period had higher viral load at presentation and required longer duration to achieve a negative PCR swab, compared to those infected in the pre-delta variant period. Time to achieve negative PCR swab was longest in unvaccinated individuals infected during delta-variant period. However, vaccinated and unvaccinated individuals achieved high PCR cycle threshold value of ≥25 and ≥30 at similar timing.

CONCLUSION

Our study suggests that patients infected during delta-variant period of COVID-19 illness, have higher viral load at presentation and prolonged viral shedding, especially in the unvaccinated cohort. However, prolonged time to negative PCR is likely due to inactive virus shedding, and that conversion to negative PCR may not be a necessary pre-requisite for de-isolation.

BNT162b2 vaccine effectiveness in chronic kidney disease patients – an observational study

Background

chronic kidney disease (CKD) is a risk factor for severe COVID-19. We aimed to evaluate real-life effectiveness of the BNT162b2 mRNA vaccine for a range of outcomes in patients with CKD compared to matched controls.

Methods

Data from Israel's largest healthcare organization were retrospectively used. Vaccinated CKD (eGFR&lt;60ml/min/1.73m2) and maintenance dialysis patients were matched to vaccinated controls without CKD (eGFR&gt; = 60ml/min/1.73m2) according to demographic and clinical characteristics. Study outcomes included documented infection with SARS-CoV-2, symptomatic infection, COVID-19 related hospitalization, severe disease, and death. Vaccine effectiveness was estimated as the risk ratio [RR] at days 7-28 following the second vaccine dose, using the Kaplan–Meier estimator. Effectiveness measures were also evaluated separately for various stages of CKD.

Results

There were 67,861 CKD patients not treated with dialysis, 2,606 hemodialysis patients, and 70,467 matched controls. The risk of sever disease (RR1.84, 95% CI 0.95-2.67) and death (RR 2.00, 95% CI 0.99-5.20) was increased in non-dialysis CKD patients compared with controls without CKD following vaccination.

For the subgroup of patients with eGFR below 30 ml/min/1.73m2, the risk of severe disease and death was increased compared to controls (RR 6.42, 95% CI 1.85-17.51 and RR 8.81, 95% CI 1.63-13.81, respectively). The risks for all study outcomes was increased in hemodialysis patients, compared with controls.

Conclusion

Two doses of the BNT162b2 vaccine were found less efficient for patients with eGFR&lt;30ml/min/1.73m2. Risk in hemodialysis patients is increased for all outcomes. These results suggest prioritizing patients with eGFR&lt;30ml/min/1.73m2 for booster shots, pre and post exposure prophylaxis, and early COVID-19 therapy.

Neutralizing antibody response against the B.1.617.2 (delta) and the B.1.1.529 (omicron) variants after a third mRNA SARS-CoV-2 vaccine dose in kidney transplant recipients

Seroconversion after COVID-19 vaccination is impaired in kidney transplant recipients. Emerging variants of concern such as the B.1.617.2 (delta) and the B.1.1.529 (omicron) variants pose an increasing threat to these patients. In this observational cohort study, we measured anti-S1 IgG, surrogate neutralizing, and anti-receptor-binding domain antibodies three weeks after a third mRNA vaccine dose in 49 kidney transplant recipients and compared results to 25 age-matched healthy controls. In addition, vaccine-induced neutralization of SARS-CoV-2 wild-type, the B.1.617.2 (delta), and the B.1.1.529 (omicron) variants was assessed using a live-virus assay. After a third vaccine dose, anti-S1 IgG, surrogate neutralizing, and anti-receptor-binding domain antibodies were significantly lower in kidney transplant recipients compared to healthy controls. Only 29/49 (59%) sera of kidney transplant recipients contained neutralizing antibodies against the SARS-CoV-2 wild-type or the B.1.617.2 (delta) variant and neutralization titers were significantly reduced compared to healthy controls (p < 0.001). Vaccine-induced cross-neutralization of the B.1.1.529 (omicron) variants was detectable in 15/35 (43%) kidney transplant recipients with seropositivity for anti-S1 IgG, surrogate neutralizing, and/or anti-RBD antibodies. Neutralization of the B.1.1.529 (omicron) variants was significantly reduced compared to neutralization of SARS-CoV-2 wild-type or the B.1.617.2 (delta) variant for both, kidney transplant recipients and healthy controls (p < .001 for all).

Durability of Humoral and Cellular Immunity after an Extended Primary Series with Heterologous Inactivated SARS-CoV-2 Prime-Boost and ChAdOx1 nCoV-19 in Dialysis Patients (ICON3)

The durability of a three-dose extended primary series of COVID-19 vaccine in dialysis patients remains unknown. Here, we assessed dynamic changes in SARS-CoV-2-specific humoral and cell-mediated immunity at baseline, 3 months, and 6 months after the extended primary series in 29 hemodialyzed (HD), 28 peritoneal dialyzed (PD) patients, and 14 healthy controls. Participants received two doses of inactivated SARS-CoV-2 vaccine followed by a dose of ChAdOx1 nCoV-19 vaccine. At 6 months, median anti-RBD IgG titers (IQR) significantly declined from baseline in the HD (1741 (1136−3083) BAU/mL vs. 373 (188−607) BAU/mL) and PD (1093 (617−1911) BAU/mL vs. 180 (126−320) BAU/mL) groups, as did the mean percent inhibition of neutralizing antibodies (HD: 96% vs. 81%; PD: 95% vs. 73%) (all p < 0.01). Age and post-vaccination serological response intensity were predictors of early humoral seroprotection loss. In contrast, cell-mediated immunity remained unchanged. In conclusion, humoral immunity declined substantially in dialysis patients, while cell-mediated immunity remained stable 6 months after the extended heterologous primary series of two inactivated SARS-CoV-2/ChAdOx1 nCoV-19 vaccine. A booster dose could be considered in dialysis patients 3 months after this unique regimen, particularly in the elderly or those with a modest initial humoral response.

Early Humoral Responses of Hemodialysis Patients After Inactivated SARS-CoV-2 Vaccination

Purpose

To detect antibody responses to inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine in patients undergoing hemodialysis and to investigate vaccine-related adverse events.

Patients and Methods

A total of 120 hemodialysis (HD) patients and 24 healthy controls (HCs) who had not been previously infected with SARS-CoV-2 and had received their first dose of the inactivated vaccine (CoronaVac; Sinovac Biotech Ltd) were recruited for this study. All participants were scheduled to receive a second dose of inactivated SARS-CoV-2 vaccine. Serum-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies against the SARS-CoV-2 were detected at least 14 days after the second dose of vaccine using a commercial kit. Positive and negative results were defined as a sample/cutoff (S/CO) ratio≥1.00 and <1.00, respectively. Vaccination-related adverse events were assessed using a standardized questionnaire.

Results

There were no significant differences regarding the seroprevalences of IgG and IgM antibodies against SARS-CoV-2 and the self-reported vaccination-related adverse events between HD patients and HCs. The analysis results for HD patients suggest that 82 (68.3%) and 27 (22.5%) tested positive for IgG and IgM, respectively. The levels of IgG were higher than IgM levels (P<0.0001). In addition, the IgG-positive group had significantly higher serum albumin levels than the IgG-negative group (P<0.05). Only mild vaccine-related adverse events were observed in two patients (1.66%) and in one healthy individual (4.2%).

Conclusion

The seroprevalences of IgG and IgM antibodies against SARS-CoV-2 and vaccination-related adverse effects are similar between HD and HCs. The inactivated SARS-CoV-2 vaccine is effective and safe in inducing near-term immunity in hemodialysis patients.

Impact of the COVID-19 pandemic on patients with chronic kidney disease: A narrative review

ABSTRACT

Severe acute respiratory disease coronavirus 2 is currently causing the coronavirus disease 2019 (COVID-19) pandemic, placing extreme strain on the global health system. Vaccination is the main measure for preventing the COVID-19 epidemic, especially for high-risk groups including patients with chronic kidney disease (CKD). However, CKD patients receiving dialysis or kidney transplant may be characterized by decreased renal function and immune disorders, which may have uncertainties in their health. This overview aims to introduce the possible impact of the COVID-19 vaccine on kidney disease and its application in patients with CKD to provide evidence for the COVID-19 vaccine in patients with CKD. The data for this study were collected from PubMed, Cochrane Library, Embase, ClinicalTrials.gov, and the China Knowledge Resource Integrated Database (CNKI). The following keywords were used: "COVID-19", "COVID-19 vaccine," and "CKD". The publication time of the papers was set from the establishment of the databases to September 2021. A total of 47 studies were included, and patients with CKD are a high-risk group for COVID-19 infection and severe illness. Vaccination is a powerful tool for preventing CKD patients from COVID-19. Because of possible side effects, the recurrence or deterioration of kidney disease may occur in CKD patients after vaccination. Although vaccination for patients with CKD remains a problem, with the advantages outweighing the disadvantages, stable CKD patients should complete a vaccination plan, and doctors should be aware of the recurrence or deterioration of kidney disease and close monitoring.

DATA ACCESS STATEMENT

Research data supporting this publication are available from the electronic databases of PubMed, Cochrane Library, Embase, ClinicalTrials.gov, and the China Knowledge Resource Integrated Database (CNKI).

ChAdOx1 nCoV-19 Immunogenicity and Immunological Response Following COVID-19 Infection in Patients Receiving Maintenance Hemodialysis

Patients with end-stage renal disease (ESRD) receiving hemodialysis (HD) were found to have a decreased immune response following mRNA COVID-19 immunization. ChAdOx1 nCoV-19 was a promising COVID-19 vaccine that performed well in the general population, but the evidence on immunogenicity in ESRD with HD patients was limited. Moreover, the immunological response to COVID-19 infection was inconclusive in patients with ESRD and HD. The aim of this study was to investigate the immunogenicity of ChAdOx1 nCoV-19 vaccination and the immunological response after COVID-19 infection in ESRD patients with HD. The blood samples were obtained at baseline, 1-month, and 3-month follow-up after each shot or recovery. All participants were measured for anti-spike IgG by the ELISA method, using Euroimmun. This study found a significant increase in anti-spike IgG after 1 month of two-shot ChAdOx1 nCoV-19 vaccination, followed by a significant decrease after 3 months. On the other hand, the anti-spike IgG was maintained in the post-recovery group. There was no significant difference in the change of anti-spike IgG between the one-shot ChAdOx1 nCoV-19-vaccinated and post-recovery groups for both 1-month and 3-month follow-ups. The seroconversion rate for the vaccinated group was 60.32% at 1 month after one-shot vaccination and slightly dropped to 58.73% at the 3-month follow-up, then was 92.06% at 1 month after two-shot vaccination and reduced to 82.26% at the 3-month follow-up. For the recovered group, the seroconversion rate was 95.65% at 1 month post-recovery and 92.50% at 3-month follow-up. This study demonstrated the immunogenicity of two-dose ChAdOx1 nCoV-19 in ESRD patients with HD for humoral immunity. After COVID-19 infection, the humoral immune response was strong and could be maintained for at least three months.

Factors associated with SARS-CoV-2 antibody titers and prognosis of breakthrough infection in hemodialysis patients

BACKGROUND

The mortality rate of Coronavirus disease 2019 (COVID-19) is extremely high in hemodialysis patients (HDP). These patients also develop lower antibody titers after vaccination. Therefore, factors associated with antibody titers and vaccine efficacy in HDP with breakthrough infection need to be investigated.

METHODS

We measured anti-S1 antibody titers in HDP (n = 104) and controls (n = 35), evaluating the influence of background on HDP by multivariable regression analysis. We classified 26 HDP patients admitted with COVID-19 into the unvaccinated (n = 15) and breakthrough infection group (n = 11), performing between-group comparisons of laboratory findings and prognosis. Vaccinated COVID-19 patients were classified into HDP and non-HDP controls, and compared the relationship between antibody titer and severity, and the prognosis of breakthrough infection.

RESULTS

The antibody titer was significantly lower in the HDP group than in the control group. Among HDP, age and smoking history were significantly independent factors associated with antibody titer. The breakthrough infection group had significantly better laboratory findings (KL-6 and LDH), severity, and hospitalization period than the unvaccinated group even if antibody titers were lower than the known threshold for neutralization (p < 0.05). There was no significant difference in prognosis between the HDP and non-HDP with breakthrough infection. Severity of COVID-19 tended to be higher with lower antibody titer in non-HDP, but not in HDP.

CONCLUSION

Vaccines improved the severity of COVID-19 and hospitalization period of breakthrough infection in HDP, although HDP, especially in elderly smokers had lower antibody titers than control. There was no significant association between antibody titer and severity in HDP.

Humoral response and breakthrough infections with SARS-CoV-2 B.1.617.2 variant in vaccinated maintenance hemodialysis patients

INTRODUCTION

Breakthrough COVID-19 may occur in vaccinated people, and may result from declining vaccine effectiveness or highly transmittable SARS-CoV-2 variants, such as the B.167.2 (delta) variant. We investigated risk factors and outcomes for infection with the delta variant among vaccinated hemodialysis patients.

METHODS

Patients on maintenance hemodialysis who received two doses of the BNT162b2 (Pfizer-BioNTech) vaccine were analysed according to having developed COVID-19 (study group) or not (control group), in a retrospective, observational, comparative study. We compared risk-factors for developing breakthrough COVID-19 and assessed clinical outcomes, including 30-day mortality rates.

RESULTS

Twenty-four cases of breakthrough SARS-CoV-2 infection were compared to 91 controls without infection. Breakthrough infection was associated with chronic immunosuppressive treatment, hematological malignancies, and low antibody levels against SARS-CoV-2 spike protein. All COVID-19 cases occurred at least 5 months after vaccination, and most were caused by the B.1.617.2 variant (at least 23/24 cases). COVID-19 was categorized as severe or critical disease in 11/24 patients (46%), and 54% required hospitalization and COVID-19-directed treatment. The source of infection was nosocomial in 6/24 cases (25%), and healthcare-related in 3/24 (12.5%). Mortality rate was 21%. Overall mortality was significantly higher in patients who developed COVID-19 than in controls (odds ratio for all-cause mortality 7.6, 95% CI 1.4-41, p = 0.002).

CONCLUSIONS

Breakthrough COVID-19 with the B.1.617.2 variant can occur in vaccinated hemodialysis patients and is associated with immunosuppression and weaker humoral response to vaccination. Infections may be nosocomial and result in significant morbidity and mortality.

Heterologous immunization with BNT162b2 followed by mRNA-1273 in dialysis patients: seroconversion and presence of neutralizing antibodies

INTRODUCTION

The vital renal replacement therapy makes it impossible for dialysis patients to distance themselves socially. This results in a high risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and developing coronavuris disease 2019, with excess mortality due to disease burden and immunosuppression. We determined the efficacy of a 100-µg booster of mRNA-1273 (Moderna, Cambridge, MA, USA) 6 months after two doses of BNT162b2 (BioNTech/Pfizer, Mainz, Germany/New York, USA) in 194 SARS-CoV-2-naïve dialysis patients.

METHODS

Anti-SARS-CoV-2 spike antibodies were measured with the Elecsys Anti-SARS-CoV-2 S assay (Roche Diagnostics, Mannheim, Germany) 4 and 10-12 weeks after two doses of BNT162b2 as well as 4 weeks after the mRNA-1273 booster. The presence of neutralizing antibodies was measured by the SARS-CoV-2 Surrogate Virus Neutralization Test (GenScript Biotech, Piscataway, NJ, USA). Two different cut-offs for positivity were used, one according to the manufacturer's specifications and one correlating with positivity in a plaque reduction neutralization test (PRNT). Receiver operating characteristics analyses were performed to match the anti-SARS-CoV-2 spike antibody cut-offs with the cut-offs in the surrogate neutralization assay accordingly.

RESULTS

Any level of immunoreactivity determined by the anti-SARS-CoV-2 spike antibody assay was found in 87.3% (n = 144/165) and 90.6% (n = 164/181) of patients 4 and 10-12 weeks, respectively, after two doses of BNT162b2. This was reduced to 68.5% or 60.6% 4 weeks and 51.7% or 35.4% 10-12 weeks, respectively, when using the ROC cut-offs for neutralizing antibodies in the surrogate neutralization test (manufacturer's cut-off ≥103 U/mL and cut-off correlating with PRNT ≥196 U/mL). Four weeks after the mRNA-1273 booster, the concentration of anti-SARS-CoV-2 spike antibodies increased to 23 119.9 U/mL and to 97.3% for both cut-offs of neutralizing antibodies.

CONCLUSION

Two doses of BNT162b2 followed by one dose of mRNA-1273 within 6 months in patients receiving maintenance dialysis resulted in significant titres of SARS-CoV-2 spike antibodies. While two doses of mRNA vaccine achieved adequate humoral immunity in a minority, the third vaccination boosts the development of virus-neutralizing quantities of SARS-CoV-2 spike antibodies (against wild-type SARS-CoV-2) in almost all patients.

Differences in Humoral and Cellular Vaccine Responses to SARS-CoV-2 in Kidney and Liver Transplant Recipients

The antibody and T cell responses after SARS-CoV-2 vaccination have not been formally compared between kidney and liver transplant recipients. Using a multiplex assay, we measured IgG levels against 4 epitopes of SARS-CoV-2 spike protein and nucleocapsid (NC) antigen, SARS-CoV-2 variants, and common coronaviruses in serial blood samples from 52 kidney and 50 liver transplant recipients undergoing mRNA SARS-CoV-2 vaccination. We quantified IFN-γ/IL-2 T cells reactive against SARS-CoV-2 spike protein by FluoroSpot. We used multivariable generalized linear models to adjust for the differences in immunosuppression between groups. In liver transplant recipients, IgG levels against every SARS-CoV-2 spike epitope increased significantly more than in kidney transplant recipients (MFI: 19,617 vs 6,056; P<0.001), a difference that remained significant after adjustments. Vaccine did not affect IgG levels against NC nor common coronaviruses. Elicited antibodies recognized all variants tested but at significantly lower strength than the original Wuhan strain. Anti-spike IFN-γ-producing T cells increased significantly more in liver than in kidney transplant recipients (IFN-γ-producing T cells 28 vs 11 spots/5x10⁵ cells), but this difference lost statistical significance after adjustments. SARS-CoV-2 vaccine elicits a stronger antibody response in liver than in kidney transplant recipients, a phenomenon that is not entirely explained by the different immunosuppression.

Immunogenicity and Safety of COVID-19 Vaccines in Patients Receiving Renal Replacement Therapy: A Systematic Review and Meta-Analysis

Background

Systematic data on the efficacy and safety of COVID-19 vaccine in patients on renal replacement therapy (RRT) remains limited. We conducted a meta-analysis on the efficacy and safety of COVID-19 vaccine in patients on RRT.

Methods

Eligible studies were identified by systematic literature search in four electronic databases. Twenty-seven studies (4,264 patients) were included for meta-analysis. 99% patients received mRNA vaccine.

Results

Patients on RRT showed inferior seropositivity after two-dosed COVID-19 vaccine, 44% lower than the general population. Kidney transplant recipients (KTRs) had significantly lower seropositivity than patients on haemodialysis (HD) or peritoneal dialysis (PD) (26.1 vs. 84.3% and 92.4% respectively, p < 0.001 for both). Compared with healthy controls, KTRs, HD and PD patients were 80% (95% CI: 62–99%), 18% (95% CI: 9–27%) and 11% (95% CI: 1–21%) less likely to develop antibodies after vaccination (p < 0.001, <0.001 and 0.39 respectively). In KTRs, every 1% increase in using mycophenolate was associated with 0.92% reduction in seropositivity (95% CI: −1.68, −0.17, p = 0.021) at population level. The overall adverse event rate attributed to vaccination was 2.1%. Most events were mild.

Conclusion

Patients on RRT, particularly KTRs, had significantly reduced antibody response after two-dosed COVID-19 vaccination. Vaccination is generally well tolerated.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier: CRD42021261879.

Humoral Response in Hemodialysis Patients Following COVID-19 Vaccination and Breakthrough Infections during Delta and Omicron Variant Predominance

Background: The advancement of COVID-19 vaccination programs globally has been viewed as an integral strategy to reduce both the number of COVID-19 cases and consequential complications of COVID-19, particularly for high-risk patient groups. There are limited data on the antibody response and protection from disease infection and severity in patients requiring hemodialysis (HD) following COVID-19 vaccination during the Delta and Omicron variant predominance. We conducted a study aiming to evaluate humoral immunity derived from two different COVID-19 vaccines administered to our in-centre HD population and investigated the characteristics of breakthrough COVID-19 infections occurring post-vaccination within this population. Methods: This is a prospective observational study including patients receiving HD at Salford Royal Hospital. The first and second doses of COVID-19 vaccinations (Pfizer BioNTech BNT162b2 or Oxford AstraZeneca ChAdOx1 nCoV-19) were administered to this patient cohort since January 2021. The incidence of any breakthrough COVID-19 infections occurring in double vaccinated patients between 1 April 2021 and 15 January 2022 was recorded. Patients were screened weekly with nasal and pharyngeal nasopharyngeal swabs for real-time Reverse Transcription Polymerase Chain Reaction (rRT-PCR) for COVID-19, whilst SARS-CoV-2 antibody testing was performed alongside monthly routine HD bloods. Results: Four hundred eleven patients receiving HD were included in this study, of which 170 of 178 patients (95.5%) with available data on antibody status following two doses of the Pfizer BioNTech BNT162b2 vaccination had detectable antibody response, whilst this was the case for 97 of 101 patients (96.1%) who received two doses of the Oxford AstraZeneca ChAdOx1 nCoV-19 vaccine. For 12 seronegative patients who received a booster vaccine (third dose), nine seroconverted, while one remained negative and two were not tested. No statistically significant differences were observed with regards to antibody status between those receiving Pfizer BioNTech BNT162b2 and Oxford AstraZeneca ChAdOx1 nCoV-19 vaccines. Sixty-three of 353 patients with two doses of COVID-19 vaccination had breakthrough COVID-19 infection (40 during Delta and 23 during Omicron variant predominance). Of the 40 patients during the delta period, five were admitted into hospital and there were two reported deaths due to COVID-19-related illness. There were no COVID-19 associated hospitalizations or deaths during the Omicron variant predominance. Conclusions: The vast majority of HD patients who received two doses of the Pfizer BioNTech BNT162b2 or Oxford AstraZeneca ChAdOx1 nCoV-19 vaccinations developed detectable antibody responses. Our results support the value of booster vaccination with mRNA-based COVID-19 vaccine in HD patients and highlight the need for ongoing surveillance programmes with rRT-PCR and antibody testing for timely detection of positive cases.

Impaired Neutralizing Antibody Activity against B.1.617.2 (Delta) after Anti-SARS-CoV-2 Vaccination in Patients Receiving Anti-CD20 Therapy

Background: To characterize humoral response after standard anti-SARS-CoV-2 vaccination in Rituximab-treated patients and to determine the optimal time point after last Rituximab treatment for appropriate immunization. Methods: Sixty-four patients who received Rituximab within the last seven years prior to the first anti-SARS-CoV-2 vaccination were recruited in a prospective observational study. Anti-S1 IgG, SARS-CoV-2 specific neutralization, and various SARS-CoV-2 target antibodies were determined. A live virus assay was used to assess neutralizing antibody activity against B.1.617.2 (delta). In Rituximab-treated patients, CD19+ peripheral B-cells were quantified using flow cytometry. Results: After second vaccination, all antibodies were significantly reduced compared to healthy controls. Neutralizing antibody activity against B.1.617.2 (delta) was detectable with a median (IQR) ID50 of 0 (0−1:20) compared to 1:320 (1:160−1:320) in healthy controls (for all p < 0.001). Longer time period since last Rituximab administration correlated with higher anti-SARS-CoV-2 antibody levels and a stronger neutralization of B.1.617.2 (delta). With one exception, only patients with a CD19+ cell proportion ≥ 1% had detectable neutralizing antibodies. Conclusion: Our data indicate that a reconstitution of the B-cell population to >1% seems crucial in developing neutralizing antibodies against SARS-CoV-2. We suggest that anti-SARS-CoV-2 vaccination should be administered at least 8−12 months after the last Rituximab treatment for sufficient humoral responses.

Neutralizing Antibody Activity Against the B.1.617.2 (delta) Variant Before and After a Third BNT162b2 Vaccine Dose in Hemodialysis Patients

Hemodialysis patients are at high risk for severe COVID-19, and impaired seroconversion rates have been demonstrated after COVID-19 vaccination. Humoral immunity wanes over time and variants of concern with immune escape are posing an increasing threat. Little is known about protection against the B.1.617.2 (delta) variant of concern in hemodialysis patients before and after third vaccination. We determined anti-S1 IgG, surrogate neutralizing, and IgG antibodies against different SARS-CoV-2 epitopes in 84 hemodialysis patients directly before and three weeks after a third vaccine dose with BNT162b2. Third vaccination was performed after a median (IQR) of 119 (109–165) days after second vaccination. In addition, neutralizing activity against the B.1.617.2 (delta) variant was assessed in 31 seroconverted hemodialysis patients before and after third vaccination. Triple seropositivity for anti-S1 IgG, surrogate neutralizing, and anti-RBD antibodies increased from 31/84 (37%) dialysis patients after second to 80/84 (95%) after third vaccination. Neutralizing activity against the B.1.617.2 (delta) variant was significantly higher after third vaccination with a median (IQR) ID₅₀ of 1:320 (1:160–1:1280) compared with 1:20 (0–1:40) before a third vaccine dose (P<0.001). The anti-S1 IgG index showed the strongest correlation with the ID₅₀ against the B.1.617.2 (delta) variant determined by live virus neutralization (r=0.91). We demonstrate low neutralizing activity against the B.1.617.2 (delta) variant in dialysis patients four months after standard two-dose vaccination but a substantial increase after a third vaccine dose. Booster vaccination(s) should be considered earlier than 6 months after the second vaccine dose in immunocompromised individuals.

Diminished and waning immunity to COVID-19 vaccination among hemodialysis patients in Israel: the case for a third vaccine dose

Background

Humoral responses to coronavirus disease 2019 (COVID-19) vaccines in hemodialysis (HD) patients can direct vaccination policy.

Methods

We compared 409 COVID-19-naïve HD patients from 13 HD units in Israel to 148 non-dialysis-dependent COVID-19-naïve controls. Twenty-four previously infected (antinucleocapsid positive) HD patients were analysed separately. Blood samples were obtained ≥14 days post-vaccination (BNT162b2, Pfizer/BioNTech) to assess seroconversion rates and titers of anti-spike (anti-S) and neutralizing antibodies.

Results

The median time from vaccination to blood sample collection was 82 days [interquartile range (IAR) 64-87] and 89 days (IQR 68-96) for HD patients and controls, respectively. Seroconversion rates were lower in HD patients compared with controls for both anti-S and neutralizing antibodies (89% and 77% versus 99.3%, respectively; P < 0.0001). Antibody titers were also significantly lower in HD patients compared with controls {median 69.6 [IQR 33.2-120] versus 196.5 [IQR 118.5-246], P < 0.0001; geometric mean titer [GMT] 23.3 [95% confidence interval (CI) 18.7-29.1] versus 222.7 [95% CI 174-284], P < 0.0001, for anti-S and neutralizing antibodies, respectively}. Multivariate analysis demonstrated dialysis dependence to be strongly associated with lower antibody responses and antibody titers waning with time. Age, low serum albumin and low lymphocyte count were also associated with lower seroconversion rates and antibody titers. HD patients previously infected with sudden acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had no difference in their seroconversion rates or antibody titers compared with COVID-19-naïve patients.

Conclusion

This study demonstrates diminished and waning humoral responses following COVID-19 vaccination in a large and diverse cohort of HD patients, including those previously infected with SARS-CoV-2. Considering these results and reduced vaccine effectiveness against variants of concern, in addition to continued social distancing precautions, a third booster dose should be considered in this population.

Neutralizing antibody activity against the B.1.617.2 (delta) variant 8 months after two-dose vaccination with BNT162b2 in health care workers

Objectives

Methods

Results

Discussion

Immunogenicity and reactogenicity of homologous mRNA-based and vector-based SARS-CoV-2 vaccine regimens in patients receiving maintenance dialysis

Patients receiving maintenance dialysis (MD) are vulnerable to COVID-19-related morbidity and mortality. Currently, data on SARS-CoV-2-specific cellular and humoral immunity post-vaccination in this population are scarce.

We conducted a prospective single-center study exploring the specific cellular (interferon-γ and interleukin-2 ELISpot assays) and humoral immune responses (dot plot array and chemiluminescent microparticle immunoassay [CMIA]) at 4 weeks and 6 weeks following a single dose or a complete homologous dual dose SARS-CoV-2 vaccine regimen in 60 MD patients (six with a history of COVID-19).

Our results show that MD patients exhibit a high seroconversion rate (91.7%) but the anti-spike IgG antibodies (CMIA) tend to wane rapidly after full immunization. Only 51.7% of the patients developed T cell immune response. High anti-spike IgG antibodies may predict a better cellular immunity. While patients with prior COVID-19 showed the best response after one, SARS-CoV-2-naïve patients may benefit from a third vaccine injection.

Immunological and clinical efficacy of COVID-19 vaccines in immunocompromised populations: a systematic review

BACKGROUND

Available data show that COVID-19 vaccines may be less effective in immunocompromised populations, who are at increased risk of severe COVID-19.

OBJECTIVES

We conducted a systematic review of literature to assess immunogenicity, efficacy and effectiveness of COVID-19 vaccines in immunocompromised populations.

DATA SOURCES

We searched Medline and Embase databases.

STUDY ELIGIBILITY CRITERIA, PATIENTS, INTERVENTIONS

We included studies of COVID-19 vaccines after complete vaccination in immunocompromised patients until 31 August 2021. Studies with <10 patients, safety data only and case series of breakthrough infections were excluded.

METHODS

Risk of bias was assessed via the tool developed by the National Institutes of Health on interventional and observational studies. Immunogenicity was assessed through non-response rate defined as no anti-SARS-CoV-2 spike protein antibodies, efficacy and effectiveness by the relative reduction in risk of SARS-CoV-2 infection or COVID-19. We collected factors associated with the risk of non-response. We presented collected data by immunosuppression type.

RESULTS

We screened 5917 results, included 162 studies. There were 157 on immunogenicity in 25 209 participants, including 7835 cancer or haematological malignancy patients (31.1%), 6302 patients on dialysis (25.0%), 5974 solid organ transplant recipients (23.7%) and 4680 immune-mediated disease patients (18.6%). Proportion of non-responders seemed higher among solid organ transplant recipients (range 18-100%) and patients with haematological malignancy (range 14-61%), and lower in patients with cancer (range 2-36%) and patients on dialysis (range 2-30%). Risk factors for non-response included older age, use of corticosteroids, immunosuppressive or anti-CD20 agent. Ten studies evaluated immunogenicity of an additional dose. Five studies evaluated vaccine efficacy or effectiveness: three on SARS-CoV-2 infection (range 71-81%), one on COVID-19-related hospitalization (62.9%), one had a too small sample size.

CONCLUSIONS

This systematic review highlights the risk of low immunogenicity of COVID-19 vaccines in immunocompromised populations, especially solid organ transplant recipients and patients with haematological malignancy. Despite lack of vaccine effectiveness data, enhanced vaccine regimens may be necessary.