Humoral and Cellular Immune Response After a 3-Dose Heterologous SARS-CoV-2 Vaccination Using the mRNA-BNT162b2 and Viral Vector Ad26COVS1 Vaccine in Hemodialysis Patients.

Background: Due to the waning humoral response after a two-dose SARS-CoV-2 mRNA vaccination, a third booster was recommended in hemodialyis patients. Data on a heterologous mRNA-vector regimen, which might improve immunogenicity, are very limited. Methods: In this observational study 36 chronic hemodialysis patients (mean (SD) age 66.9 (15.9) years, 33.3% females) were followed up for 13 months. All patients were vaccinated twice using the mRNA-BNT162b2 vaccine, followed by a 3rd dose of the vector vaccine Ad26COVS1 eight months later. We assessed the humoral response by quantifying the anti-SARS-CoV-2 spike IgG antibody and neutralizing antibody concentrations. The cellular immune response was evaluated via SARS-CoV-2 spike protein-specific interferon-γ release assay. Results: The seroconversion rate was 47.2%, 100%, 69.4% and 100% one month after the 1st dose, one and six months after the 2nd dose and four months after the heterologous 3rd dose. The median (Q1, Q3) anti-SARS-CoV-2 spike IgG concentrations at the same time were 28.7 (13.2, 69.4) BAU/ml, 1130.0 (594.5, 1735.0) BAU/ml, 89.7 (26.4, 203.8) BAU/ml, and 2080.0 (1062.5, 2080.0) BAU/ml. The percentage of patients with neutralizing antibodies was 58.3% after the 2nd dose and improved to 100% after the 3rd dose (P <0.001). A positive T-cell response was found in 50% of patients after the 3rd dose. Conclusions: A third heterologous booster dose helped to sustain humoral immunity in almost all hemodialysis patients and induced a significant T-cellular response in half of them. Stimulating the immune response against SARS-CoV-2 by two different vaccine platforms seems to be a promising approach.

Ochrobactrum anthropi infection in dialysis patients: A case report and literature summary.

INTRODUCTION: Ochrobactrum anthropi, a ubiquitous Gram-negative bacterium of low virulence, is an increasingly recognized cause of infection in immunocompromised hosts such as patients with kidney failure treated by dialysis. CASE REPORT: We report the case of a male hemodialysis patient with a central venous catheter, who developed an asymptomatic blood stream infection caused by Ochrobactrum anthropi. The infection was cured, and the dialysis catheter salvaged with intravenous meropenem and an antibiotic lock solution with ciprofloxacin. CONCLUSION: We identified 13 further cases of Ochrobactrum infection in hemodialysis patients and 10 cases in peritoneal dialysis patients in the literature. Antibiotic treatment depends on the results of susceptibility testing. In many patients, however, removal of the central venous or peritoneal dialysis catheter is required to cure the infection.

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.

How Hemodialysis Patients Perceive the SARS-CoV-2 Health Crisis: Lessons from Austria.

Background: The ongoing SARS-CoV-2 pandemic forced many countries to implement strict and unprecedented precautions to stop the spread of the virus. On top of these measures, hemodialysis units have adopted their own rules to protect wards and patients from infection with SARS-CoV-2. Despite the rapidly growing knowledge on epidemiology, virology, and clinical disease, little is known about how these measures are perceived by patients themselves on hemodialysis. Methods: The study was performed in the three hemodialysis units in Vorarlberg, Austria's westernmost state. A questionnaire was developed consisting of 22 questions on patients' perceptions of the COVID-19 crisis and their feelings about the general precautions and specific steps implemented on dialysis wards. All adult patients were asked to fill out the questionnaire anonymously. Results: Of 202 patients on hemodialysis, 148 completed the questionnaire (66.9% men, mean age 68.3±13.3 years). The vast majority (83.1%) were worried by the COVID-19 crisis, but only 28.4% reported a negative effect on emotional well-being. Daily life was most affected by the general ban on visitors (58.6%) and home confinement (35.9%). Of the patients, 64.2% feared contracting COVID-19, 30.7% were afraid of financial consequences, and 14.6% were afraid of loneliness and isolation. The safety measures on dialysis wards were classified as adequate by 97.3% of the respondents. Of the patients, 78.2% felt safe during dialysis treatment. All dialysis-specific precautions (individual patient transport, health check, hand disinfection, wearing a face mask, and physical distancing) were rated important or very important by almost all patients. To date, none of the patients have acquired SARS-CoV-2 infection. Conclusions: Although the SARS-CoV-2 crisis brought worry to and affected the lives of most patients on hemodialysis, its effect on their emotional well-being was moderate. Patients felt safe on dialysis wards, and acceptance of specific precautions was high.