ABSTRACT
Background and ObjectivesWhile most maintenance dialysis patients exhibit initial seroresponse to vaccination, concerns remain regarding the durability of this antibody response. This study evaluated immunity over time. Design, setting, participants, and measurementsThis retrospective cohort study included maintenance dialysis patients from a midsize national dialysis provider who received a complete SARS-CoV-2 vaccine series and had at least one antibody titer checked after full vaccination. Immunoglobulin G spike antibodies (SAb-IgG) titers were assessed monthly with routine labs beginning after full vaccination and followed over time; the semiquantitative SAb-IgG titer reported a range between 0 and [≥] 20 U/L. Descriptive analyses compared trends over time by prior history of COVID-19 and type of vaccine received. Time-to-event analyses were conducted for the outcome of loss of seroresponse (SAb-IgG < 1 U/L or development of COVID-19). Cox proportional hazards regression was used to adjust for additional clinical characteristics of interest. ResultsAmong 1898 maintenance dialysis patients, 1567 (84%) had no prior history of COVID-19. Patients without a history of COVID-19 had declining titers over time. Among 441 BNT162b2/Pfizer recipients, median [IQR] SAb-IgG titer declined from 20 [5.99-20] U/L in month 1 to 1.30 [0.15-3.59] U/L by month 6. Among 779 mRNA-1273/Moderna recipients, median [IQR] SAb-IgG titer declined from 20 [20-20] in month 1 to 6.20 [1.74-20] by month 6. The 347 Ad26.COV2.S/Janssen recipients had a lower titer response than mRNA vaccine recipients over all time periods. In time-to-event analyses, Ad26.COV2.S/Janssen and mRNA-1273/Moderna recipients had the shortest and longest time to loss of seroresponse, respectively. The maximum titer reached in the first two months after full vaccination was predictive of the durability of the SAb-IgG seroresponse; patients with SAb-IgG titer 1-19.99 U/L were more likely to have loss of seroresponse compared to patients with SAb-IgG titer [≥] 20 U/L (HR 23.9 [95% CI: 16.1-35.5]). ConclusionsVaccine-induced seroresponse wanes over time among maintenance dialysis patients across vaccine types. Early titers after full vaccination predict the durability of seroresponse.
ABSTRACT
ImportanceVaccines against SARS-CoV-2 are highly effective in the general population; however, their efficacy may be diminished in maintenance dialysis patients, a population particularly vulnerable to COVID-19 infection and morbidity. ObjectiveWe assessed vaccine response in a national sample of maintenance dialysis patients and identified predictors of response. DesignRetrospective cohort study Setting130 Dialysis Clinic, Inc (DCI) facilities ParticipantsMaintenance dialysis patients without known prior COVID-19 or a positive baseline antibody titer Exposure(s)Vaccine type and clinical characteristics Main Outcome(s)Using a semi-quantitative assay for antibodies against SARS-CoV-2 spike antigen, vaccine response was defined as at least one titer [≥]1 U/L between 14 and 74 days after completion of a SARS-CoV-2 vaccine series. Regression analysis was used to identify characteristics associated with response. ResultsAmong 1528 patients, 437 received BNT162b2/Pfizer vaccine, 766 received mRNA-1273/Moderna, and 325 received Ad26.COV2.S/Janssen. Serologic response differed significantly by vaccine type: 381/437 (87%) among BNT162b2/Pfizer recipients, 736/766 (96%) among mRNA-1273/Moderna recipients, and 119/325 (37%) among Ad26.COV2.S/Janssen recipients. Vaccine type, older age, immune-modulating medication, history of transplantation, and lower serum albumin were associated with vaccine non-response. Conclusions and RelevanceSerologic response to mRNA vaccines is robust among maintenance dialysis patients. Future research should evaluate durability of this response, correlation between seroresponse and protection from COVID-19, and the role of the AD26.COV2.S/Janssen vaccine in this vulnerable population.
