ABSTRACT
Introduction: It is yet not known whether COVID-19 vaccines confer a persistent humoral response in patients with chronic kidney disease. The aim of this study was to evaluate the persistence of the humoral response of antibodies in dialysis patients immunized with the COVID-19 vaccine. Method(s): A multicentre, observational and analytical study was carried out in a prospective cohort of haemodialysis patients >=18 years from six hospitals from the Autonomous City of Buenos Aires who received both components of the COVID-19 vaccine. The date of inclusion to the study was the date of the first dose. IgG antibodies against SARS-Cov-2 were measured using the "COVIDAR IgG" test, which detects antibodies specifically against two coronavirus viral antigens in blood and serum: the spike protein (S) and the binding domain to the receptor (RBD), using the ELISA technique. The COVIDAR IgG test detects qualitatively and semi-quantitatively. In the semi-quantitative determination, the values are measured in absorbance levels (AL) with a maximum of 3.3, and a lower limit of detection of 0.3. The measurements were made immediately before the administration of the first dose, 21 days after it, 21 days after the second dose, and +/- five days of the 1st booster and the 2nd booster. Quantitative data were expressed as median and interquartile range (IQR) according to their distribution. Qualitative data were expressed as absolute and relative frequencies. The analysis was performed with the software R version 4.0.3. None of the funding sources provided financial support for data collection, statistical analysis. Result(s): 102 patients were included, (49.0% female). Median age 51.6 years (IQR 39.8-62.0);41.0% were over 55 years old, 20.5% diabetic. 11 patients on peritoneal dialysis (10.7%). 15.7% (n 16) had COVID-19 prior to vaccination, with a median time from diagnosis to administration of the first dose of 7 months (IQR 6-8). The median time for the administration of the second dose was 2.8 months (IQR 2.7-2.9) and from the second dose to the 1st booster was 4.1 months (IQR 4-4.2). Patients received a 2nd booster at a median of 5.1 months (IQR 4.9-5.1) from the 1st booster. Of the 102 patients, 27 (26.5%) had positive IgG against SARS-Cov-2 at baseline. 98% of patients had positive IgG antibodies against SARS-CoV-2 21 days after the second dose (Figure 1) Among the 16 patients (15.7%) who had COVID-19 before the first component, 14 were IgG positive at baseline and only 2 were IgG non-positive 21 days after the second dose. In patients with COVID-19, antibodies at day 21 after the first component reached almost the highest levels compared to those patients who did not have COVID-19, and the rise between the last measures was lower than patients without COVID-19. In those patients, levels of antibodies dropped 21 days after the second dose and raised after the third one (figure 2). [Formula presented] [Formula presented] Conclusion(s): This study shows that vaccination against COVID-19 in dialysis patients confers immunity, which was 96% after the third dose. The decline in antibody levels in patients without COVID after the second dose highlights the importance of a booster to achieve a persistent immune response. No conflict of interestCopyright © 2023