SARS-CoV-2 vaccine effectiveness and breakthrough infections in maintenance dialysis patients

Abstract

Background: SARS-CoV-2 vaccine effectiveness during the Delta period and immunogenicity threshold associated with protection against COVID-19 related hospitalization or death in the dialysis population is unknown. Methods: A retrospective, observational study assessed SARS-CoV-2 vaccine effectiveness and immunogenicity threshold in all adult maintenance dialysis patients without COVID-19 history treated between February 1 and October 2, 2021. All COVID-19 infections, composite of hospitalization or death following COVID-19 and available SARS-CoV-2 anti-spike immunoglobulin (Ig) G values were extracted from electronic medical record. COVID-19 cases per 10,000 days at risk and vaccine effectiveness during pre-Delta and Delta periods were determined. Results: Of 15,718 patients receiving dialysis during the study period, 11,191 (71%) were fully vaccinated, 733 (5%) were partially vaccinated and 3,794 (24%) were unvaccinated. 967 COVID-19 were cases identified: 511 (53%) occurred in unvaccinated patients and 579 (60%) occurred during the Delta period. COVID-19 related hospitalization or death was less likely among vaccinated versus unvaccinated patients for all vaccines (adjusted HR 0.19 [0.12, 0.30]) and for BNT162b2/Pfizer, mRNA-1273/Moderna, and Ad26.COV2.S/Janssen (adjusted HR=0.25 [0.16, 0.40], 0.14 [0.08, 0.22], and 0.34 [0.17, 0.68] respectively). Among those with anti-spike IgG levels, those with IgG level ≥ 7 had significantly lower risk of a COVID-19 diagnosis (HR=0.25 [0.15, 0.42]) and none experienced a COVID-related hospitalization or death. Conclusions: Among maintenance dialysis patients, SARS-CoV-2 vaccination was associated with a lower risk of COVID-19 diagnosis and associated hospitalization or death. Among vaccinated patients, low anti-spike IgG level is associated with worse COVID-19 related outcomes.

Seroresponse to third doses of SARS-CoV-2 vaccine among patients receiving maintenance dialysis

“…In analyses, strata of ≥20, 7-<20, 1-<7, and <1 Index were used. The threshold of 20 reflects the semi-quantitative nature of the assay used; the threshold of 7 represents a hypothesized level of protection from severe disease 5 ; and the threshold of 1 reflects the manufacturer-recommended lower limit for defining seroresponse. 6 This study was reviewed and approved by the WCG IRB Work Order 1-1456342-1.…”

Vaccination in patients with kidney failure: lessons from COVID-19

“…Similarly, only 63% of patients receiving dialysis had neutralizing antibodies against Beta VOC after two doses of BNT162b2 (ref. 117 ) and breakthrough COVID-19 cases increased among fully vaccinated patients when the Delta VOC became dominant 118 . Interestingly, the breakthrough COVID-19 rate among fully vaccinated patients receiving dialysis was higher (1.6%) than that reported for fully vaccinated transplant recipients (0.8%) 118 , perhaps reflecting the higher SARS-CoV-2 exposure risk in patients attending dialysis centres.…”

“… 117 ) and breakthrough COVID-19 cases increased among fully vaccinated patients when the Delta VOC became dominant 118 . Interestingly, the breakthrough COVID-19 rate among fully vaccinated patients receiving dialysis was higher (1.6%) than that reported for fully vaccinated transplant recipients (0.8%) 118 , perhaps reflecting the higher SARS-CoV-2 exposure risk in patients attending dialysis centres. High exposure represents an important risk factor that should be considered in patient care, especially in the context of reduced vaccine-induced immunity.…”

“…Considering the severe clinical course and high mortality of patients with kidney failure and infections, particularly SARS-CoV-2 infection, improving seroconversion in patients with primary vaccination failure is crucial. The low vaccination response in kidney transplant recipients described above, the decline of antibody titres over time 124 , breakthrough COVID-19 in fully vaccinated patients 118 , 125 , 126 and the uncertainty of protection against VOCs led to the rollout of additional primary vaccination doses in high-risk groups, including patients receiving dialysis and kidney transplant recipients. In contrast to a booster vaccine dose, which is given after the immunity of the initial prime–boost vaccination starts to wane, additional primary vaccine doses have been provided to patients with compromised immunity to improve their initial vaccination response.…”

Seroresponse to Third Doses of SARS-CoV-2 Vaccine Among Patients Receiving Maintenance Dialysis

“…The threshold of 20 reflects the semi-quantitative nature of the assay; the threshold of 7 represents a hypothesized level of protection from severe disease. 7 This study was approved for exemption by the WCG IRB (Work Order 1-1456342-1); given the IRB exemption, no consent procedures were implemented. Statistical analyses were performed using R v4.0.2.…”