Persistence of antibody response to SARS-CoV-2 in a cohort of haemodialysis patients with COVID-19

Serological Response to SARS-CoV-2 Vaccine in Hemodialyzed Patients and the Association with Later COVID-19 Positivity

BACKGROUND

The effectiveness of the COVID-19 vaccine may differ in hemodialysis patients. The aim of this prospective multicenter study was to determine the degree of serological response to the SARS-CoV-2 vaccine in the population of dialysis patients and its association with later SARS-CoV-2 infections.

METHODS

A blood sample was taken for the determination of COVID-19 serological status (IgG antibodies) in 706 dialysis patients 16 weeks after vaccination with the second dose (Pfizer-BioNTech).

RESULTS

Only 314 (44.5%) hemodialyzed patients had a satisfactory response to the COVID-19 vaccine. Eighty-two patients (11.6%) had a borderline response, while 310 patients (43.9%) had an unsatisfactory (negative) post-vaccinal antibody titer. A longer dialysis vintage had an increased odds ratio (OR) of 1.01 for the occurrence of COVID-19 positivity after vaccination. In the group of subsequently positive patients, 28 patients (13.6%) died from complications of COVID-19. We have found differences in mean survival time between patients with and without appropriate responses to vaccination in favor of patients with a satisfactory serological response.

CONCLUSIONS

The results showed that the dialysis population will not have the same serological response to the vaccine as the general population. The majority of dialysis patients did not develop a severe clinical picture or die at the time of positivity for COVID-19.

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.

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.

Long-term trajectories of SARS-CoV-2 neutralizing antibodies and predictive value of first dose vaccination-induced IgG-antibodies in hemodialysis patients

PURPOSE

The predictive value of antibody titers after the first SARS-CoV-2 vaccination and long-term trajectories of antibody titers in hemodialysis patients are unknown.

METHODS

SARS-CoV-2 IgG antibodies and their neutralizing effect six weeks after the first and second vaccination were analysed in 30 hemodialysis patients. IgG titers served to classify participants as responders or non-responders and to calculate sensitivity, specificity, and accuracy. Associations between potential risk factors and post-vaccine non-response were analysed by Mann-Whitney-U test and Chi-Squared test. Long-term follow-up analysis (ANOVA) on the evolution of neutralizing IgG-titers was performed in 24 participants 94 and 135 days after the second immunization.

RESULTS

IgG antibodies ≥ 1 AU/L (mean 9 ± 20 AU/L) after the first dose were found in 20 patients (66.7%). After the second dose only two participants (6.7%) remained sero-negative and 16.6% showed neutralizing levels below 30%, whereas 25 patients showed IgG antibodies with the high neutralizing activity of 86 ± 18%. Positive IgG antibodies 6 weeks after the first vaccination predicted vaccination effectiveness after two cycles with a specificity of 100%, sensitivity of 76%, and accuracy of 87%. Even low-dose immunosuppressive therapy increased the relative risk for non-response after the first and second dose 1.9 (95% CI 0.8-4.6) and 4.9 (95% CI 1.0-23.8) times, respectively. Over a period of about 4.5 months IgG titers slowly declined by 51% from baseline or by 0.45 AU/mL per day, respectively.

CONCLUSION

Two cycles of SARS-CoV-2 vaccination-induced high seroconversion rates comparable to the general population. Immunosuppressive medication is a major risk factor for vaccination non-response. Mounted IgG antibodies showed a high neutralizing capacity as evidence of protective effectiveness. IgG antibodies after the first dose may serve to predict later vaccination outcome. Patients on dialysis display a more rapid decline in antibody titers on long-term follow-up compared to healthy controls.

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).

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.

Favorable Humoral Response to Third Dose of BNT162b2 in Patients Undergoing Hemodialysis

Patients undergoing hemodialysis are known to exhibit low humoral responses to vaccines against severe acute respiratory syndrome coronavirus 2. In this study, we aimed to elucidate the humoral response to the third dose of BNT162b2 (Pfizer) in patients undergoing hemodialysis. We included 279 patients undergoing hemodialysis (69 ± 11 years, 65% male, median dialysis vintage: 69 months) and 189 healthcare workers (45 ± 13 years, 30% male) who received the third dose of BNT162b2. Anti-spike immunoglobulin G (anti-S IgG) antibody levels were measured 3−4.5 months after the second dose and 3 weeks after the third dose and were compared. Despite a significant difference in anti-S IgG antibody levels after the second dose between the two groups (patients: median 215 U/mL and healthcare workers: median 589 U/mL; p < 0.001), no significant difference in anti-S IgG antibody levels after the third dose was observed (patients: median 19,000 U/mL, healthcare workers: median 21,000 U/mL). Except for dialysis vintage (ρ = 0.209, p < 0.001), no other factors correlated with anti-S IgG antibody levels after the third vaccine dose in patients undergoing hemodialysis. Therefore, a favorable response to the third dose of BNT162b2 was observed in patients undergoing hemodialysis, irrespective of their backgrounds.

Low humoral immune response to the BNT162b2 vaccine against COVID-19 in nursing home residents undergoing hemodialysis: a case-control observational study

Background

Patients on hemodialysis (HD) face a high mortality risk from coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), and they are therefore prioritized for vaccination. However, the efficacy of vaccination in this vulnerable population has not been confirmed. Although age is negatively correlated with serum immunoglobulin (Ig) levels, humoral responses to vaccination in elderly patients undergoing HD have not been investigated. To address this issue, we evaluated the anti-SARS-CoV-2 spike protein antibodies in nursing home residents on HD after BNT162b2 vaccine administration.

Methods

Patients on HD from a nursing home and care workers (controls) receiving two doses of the BNT162b2 vaccine between April and May 2021 were enrolled in this study. Those with a prior history of COVID-19 were excluded. Anti-spike protein antibodies were measured with the Elecsys (Roche) immunoassay system.

Results

The study included 26 nursing home residents (41% male; median age, 86 years) and 184 care workers (28% male; median age, 45 years). The median HD vintage was 51 months. After two doses of BNT162b2, 73% of the nursing home residents and 99.5% of the control group developed sufficient anti-spike protein antibodies (> 29 U/mL) to neutralize SARS-CoV-2. Three weeks after the second dose, median IgG titers of the residents and care workers were 83 [interquartile range (IQR) 17–511] and 1365 (IQR 847–2245) U/mL, respectively (p < 0.001).

Conclusions

The humoral response to BNT162b2 among elderly HD patients was relatively low; therefore, the optimal vaccination strategy for this population should be studied further to avoid COVID-19 outbreaks in healthcare facilities.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41100-022-00397-5.

Negative immune responses to two-dose mRNA COVID-19 vaccines in renal allograft recipients assessed with simple antibody and interferon gamma release assay cellular monitoring

Studies are urgently needed to characterize immunogenicity, efficacy, and safety of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mRNA vaccines in kidney transplant (KT) recipients, excluded from major clinical trials. Complex ELISPOT and other cellular response techniques have been applied, but simpler tools are needed. An easy-to-use real-world monitoring of SARS-CoV-2 IgG antibodies against the Spike protein and QuantiFERON^® SARS-CoV-2 IFNγ release assay (IGRA) were performed at baseline and 28 days after the second dose in KT recipients and controls (dialysis patients and healthy ones). All healthy controls and >95% dialysis controls became positive for anti-S IgG antibodies, while only 63.3% of KT patients seroconverted with a very low antibody level. A positive IGRA was documented in 96.9% of controls, 89.3% peritoneal dialysis, 77.6% hemodialysis, 61.3% of KT patients transplanted more than 1 year ago and only 36% of those transplanted within the previous 12 months. Overall, 100% of healthy controls, 95.4% of dialysis patients and 78.8% KT recipients developed any immune response (humoral and/or cellular) against SARS-CoV-2. KT patients showed low rates of immune responses to mRNA Coronavirus infectious disease 2019 vaccines, especially those with recent transplantations. Simple humoral and cellular monitoring is advisable, so that repeated doses may be scheduled according to the results.

Patients receiving hemodialysis do not lose SARS-CoV-2 antibodies more rapidly than non-renal controls: a prospective cohort study

Background

Method

Results

Conclusion

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.

Response to Vaccination Against SARS-CoV-2 in Patients With Antineutrophil Cytoplasmic Antibody-Associated Vasculitis With Renal Involvement

Background

Patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAV) present with multisystem disease including renal impairment. The treatment for AAV involves a high burden of immunosuppression. Patients with renal involvement are treated especially intensively. As a result, we identified these patients as being potentially at high risk of failure to seroconvert to COVID-19 vaccination.

Methods

We collected data on seroconversion response rates to COVID-19 vaccination in a multi-ethnic cohort of patients with AAV and renal involvement treated at a busy tertiary nephrology centre as part of a retrospective review of patient notes. Blood samples were taken following vaccination with either Pfizer or Astra-Zeneca COVID-19 vaccines and median fluorescence intensity was measured using the validated MULTICOV-Ab Magnetic Luminex^Ⓡ Assay. We also evaluated whether seroconversion was affected by immunosuppression regimen.

Results

81 patients were included. The mean age was 62, and there were 49 (60%) females. 55 patients had a blood test after the first dose; 46 after the second dose. Patients were in remission with a median BVAS of 0 (IQR 2). Seroconversion after the first dose with either vaccine was 35/55 (63.6%). After the second it was 38/46 (82.6%). Subgroup analyses revealed a trend to impaired seroconversion in non-white versus white patients (77.8 vs. 81.7% (p = 0.69) after the first dose of vaccine and in those treated with Rituximab in the last 12 months (73.3 vs. 87.1%, p = 0.41).

Conclusions

These data offer real-world evidence of lower seroconversion in response to vaccination with one dose in patients with AAV and renal involvement than the general UK population. After two doses, seroconversion is in line with national data. These data provide a rationale for hospital-led identification of patients most at risk of COVID-19 and underscore the importance of local connexions between hospitals and their communities. These data provide further support for targeting booster vaccination programmes to vulnerable patient cohorts. They add to the growing evidence of reduced seroconversion in response to vaccination in patients with renal disease of any cause.

Response to and outcomes of the Pfizer BNT162B2 vaccine in hemodialysis patients-A prospective observational study

Introduction

COVID‐19 infection is associated with high mortality among hemodialysis patients. Standard vaccine response is generally lower among these patients. The adequate antibody titer response and the outcome of COVID‐19 vaccine responders versus non‐responders are unknown.

Methods

Hemodialysis patients on maintenance hemodialysis who have received two doses of Pfizer BNT162B2 vaccine were studied. Antibody response was tested after 14 days of the second dose. LIAISON SARS‐CoV2 S1/S2 IgG test by DiaSorin (Italy) was used to assess antibody response. Patients were followed between 3 and 7 months after vaccination for COVID‐19 infection, hospitalization and death related to COVID‐19.

Findings

A total of 138 patients received two doses of Pfizer BNT162B2 vaccine. One hundred and twenty‐seven patients had adequate response to the vaccine with IgG level ≥ 15 AU/ml versus 11 patients had poor response with IgG level ≤ 15 AU/ml. The response was 92% (127/138). Patient with history of prior COVID‐19 infection had higher antibody titer mean of 339 ± 113 versus 157 ± 140 for patient with no prior history of COVID‐19.

Seven patients in both groups had COVID‐19 infection post vaccine. Among the responders, five patients had COIVD‐19 infection and two were hospitalized. These two patients had lower antibody titer of 23.9 and 75.2 AU/ml. In comparison, three patients who were not hospitalized had higher antibody titer 96.3, 118, and 319 AU/ml, respectively. In the non‐responders one patient was hospitalized and one death occurred with rate of infection of 18%.

Discussion

Seropositive patients with low antibody titer might be associated with worse outcome among responders. The ideal antibody titer level among dialysis patient is not known. Also, prior COVID‐19 infection is associated with higher response to vaccine with higher antibody titer. All non‐responders did not have prior COVID‐19 infection. More research is required to further evaluated protective antibody titer.

SARS-CoV-2-specific Humoral and Cellular Immunities in Kidney Transplant Recipients and Dialyzed Patients Recovered From Severe and Nonsevere COVID-19

Kidney transplantation and dialysis are two major risk factors for severe forms of coronavirus disease 2019 (COVID-19). The dynamics of the immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in this population remain largely unknown.

Methods

We report here the analysis of anti-SARS-CoV-2 antibody- and T cell-mediated immune responses in 26 kidney transplant recipients (KTRs) and 11 dialyzed patients (DPs) who recovered from COVID-19.

Results

After a mean time of 83 ± 26 d post-symptom onset for KTRs and 97 ± 31 d for DPs, 20 KTRs (76.9%) and 10 DPs (90.9%) displayed anti-S1 immunoglobulin G SARS-CoV-2 antibodies (P = 0.34), at similar titers in both groups. SARS-CoV-2-specific interferon-γ-producing T cells were evidenced in 26 KTRs (100%) and 10 DPs (90.9%). Total numbers of SARS-CoV-2-reactive T cells were high and not statistically different between the 2 groups. No correlation between the severity of the disease and the number of reactive T cells was found in KTRs. In 5 KTRs, also evaluated 10 mo after COVID-19, weak or absent antibody response was observed, whereas specific memory T-cell response was detected in all cases.

Conclusion

T-cell response persisted up to 3 mo post-symptom onset, even in KTRs in whom full immunosuppressive regimen was reinstated at recovery, and seems to be present up to 10 mo after infection. Our findings have implications in the understanding of the natural course of the disease in transplant patients and DPs.

Serological Response to the BNT162b2 COVID-19 mRNA Vaccine in Adolescent and Young Adult Kidney Transplant Recipients

BACKGROUND

Initial reports in adult kidney transplant recipients (KTR) indicate low immunogenicity after 2 doses of the BNT162b2 COVID-19 mRNA vaccine. We describe the immunogenicity of this vaccine compared to the serologic response in naturally infected COVID-19 positive adolescent and young adult KTR.

METHODS

For this prospective observational study, the study group included 38 KTR who received 2 doses of the tested vaccine, and the control group included 14 KTR who had a previous polymerase chain reaction-confirmed COVID-19 infection.

RESULTS

The mean age was 18 ± 3 y. Positive serologic responses were observed in 63% and 100% of the study and control groups, respectively (P = 0.01). Antibody titers were almost 30-fold higher in the control than the study group (median [interquartile range (IQR)]: 2782 [1908-11 000] versus 100.3 [4.7-1744] AU/mL, P < 0.001), despite the longer time from the COVID-19 infection to serologic testing compared to time from vaccination (median [IQR]: 157.5 [60-216] versus 37 [20.5-53] d, P = 0.011). Among vaccinated patients, higher proportions of those seronegative than seropositive were previously treated with rituximab (50% versus 8%, P = 0.01). Time from the second vaccine dose to serologic testing was longer in seropositive than seronegative patients (median [IQR]: 24.5 [15-40] versus 46 [27-56] d, P = 0.05). No patient developed symptomatic COVID-19 disease postvaccination.

CONCLUSIONS

The BNT162b2 COVID-19 mRNA vaccine yielded higher positive antibody response in adolescent and young adult KTR than previously reported for adult KTR. Antibody titers after vaccination were significantly lower than following COVID-19 infection. Longer time may be required to mount appropriate humoral immunity to vaccination in KTR.

Comparing Humoral and Cellular Adaptive Immunity during Convalescent Phase of COVID-19 in Hemodialysis Patients and Kidney Transplant Recipients

Background. It is still unclear whether COVID-19 convalescent kidney transplant recipients (KTR) and hemodialysis (HD) patients can develop anti-SARS-CoV-2 adaptive immunity. The aim was to characterize and compare the immune response to the virus in HD patients and KTR. Methods. The study included 26 HD patients and 54 KTR—both convalescent (14 HD, 25 KTR) and unexposed. The immune response was assessed by determining the anti-SARS-CoV-2 antibodies in serum and specific T cell response via the interferon-gamma release assay (IGRA). Moreover, blood-morphology-derived parameters, immune cell phenotypes, and acute phase reactants were evaluated. Results. KRT and HD convalescents presented similar serum levels of anti-SARS-CoV-2 IgG and IgA. A negative correlation occurred between IgG and time after the infection was observed. There was a strong relationship between the prevalence of anti-SARS-CoV-2 cellular and humoral responses in both groups. Convalescent IGRA response was significantly higher in HD patients compared to KTR. Conclusions. HD patients and KTR develop humoral and cellular responses after COVID-19. The antibodies levels are similar in both groups of patients. SARS-CoV-2-reactive T cell response is stronger in HD patients compared to KTR. The SARS-CoV-2-specific IgG level decreases with time while IgA and a cellular response are maintained. IGRA proved to be a valuable test for the assessment of specific cellular immunity in immunocompromised HD patients and KTR.

Haemodialysis patients show a highly diminished antibody response after COVID-19 mRNA vaccination compared with healthy controls

BACKGROUND

Haemodialysis (HD) patients are exposed to a high risk due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. They are prone to acquiring the infection and are threatened by high mortality rates in case of infection. However, HD patients were not included in the efficacy trials of the SARS-CoV-2 vaccines. Such efficacy data would have been critical because HD patients show decreased responses against various other vaccines and this could translate to the SARS-CoV-2 vaccines as well.

METHODS

We conducted a prospective cohort study that contained a group of 81 HD patients and 80 healthy controls. All of them had been vaccinated with the BioNTech/Pfizer mRNA vaccine (two doses, as per the manufacturer's recommendation). The anti-SARS-CoV-2 spike (S) antibody response was measured for all participants 21 days after the second dose. The groups were compared using univariate quantile regressions and a multivariate analysis. The adverse events (AEs) of the vaccination were assessed via a questionnaire. Finally, a correlation between the HBs-antibody response and the SARS-CoV-2 antibody response in the HD patients was established.

RESULTS

The HD patients had significantly lower anti-SARS-CoV-2 S antibody titres than the control patients 21 days after vaccination (median was 171 U/mL for dialysis patients and 2500 U/mL for the controls). Further, the HD group presented fewer AEs than the control group. No correlation was found between the antibody response to previous Hepatitis B vaccination and that of the SARS-CoV-2 vaccine.

CONCLUSIONS

HD patients present highly diminished SARS-CoV-2 S antibody titres compared with a cohort of controls. Therefore, they could be much less protected by SARS-CoV-2 mRNA vaccinations than expected. Further studies to test alternative vaccination schemes should be considered.

The Safety and Immunogenicity of the mRNA-BNT162b2 SARS-CoV-2 Vaccine in Hemodialysis Patients

Background

Hemodialysis patients are at high risk for severe COVID-19. SARS-CoV-2 vaccination related safety and immunogenicity data in these patients are rare.

Methods

In this observational study SARS-CoV-2-seronegative hemodialysis patients were vaccinated with two doses of the Pfizer/BioNTech mRNA-BNT162b2 vaccine (COMIRNATY^® 30 µg) and followed for 90 days. Local and systemic side effects were assessed at every dialysis session during the first post-vaccination week after the first and second vaccine dose. Immunogenicity was determined four weeks after vaccination by quantifying anti-SARS-CoV-2 spike protein IgG antibodies (LIAISON^® SARS-CoV-2-TrimericS IgG chemiluminescent immunoassay) expressed in binding activity units per milliliter (BAU/mL) adapted to the WHO International standard.

Results

Fifty patients (32% women, 68% men) with a mean (SD) age of 67.6 (14.8) years were included. Mild local reactions occurred in 38% after the first injection, and in 29.2% with mild, in 2.1% with moderate and in 2.1% with severe degree after the second injection. Systemic reactive events occurred less often, with diarrhea (4% mild, 4% moderate) and fatigue (8% mild) being the most frequent ones. After the first injection 42% of the patients developed a positive response using the assay specific cut-off value of 33.8 binding activity units per milliliter (BAU/mL) with a median (Q1, Q3) anti-SARS-CoV-2 spike IgG concentration of 20.0 (11.7, 51.0) BAU/mL. After the second injection the percentage of seropositive patients increased to 97.9% with an anti-SARS-CoV-2 spike IgG concentration of 1075 (290.8, 1735) BAU/mL. Higher age and immunosuppression were associated with lower, calcitriol treatment and prior seroconversion to hepatitis B vaccination with significantly higher antibody concentration.

Conclusions

The mRNA-BNT162b2 SARS-CoV-2 vaccine appears to be safe and well-tolerated and shows a high immunogenicity in hemodialysis patients.