ABSTRACT
Background: Elsewhere, we have demonstrated that the BNT162b2 vaccine (Pfizer/ BioNTech) is highly effective in reducing risk of COVID-19 among real-world dialysis patients. Because individual vaccines may be differentially available (and acceptable) to patients, it is important to understand the comparative effectiveness of other agents, such as Ad26.COV2.S (Janssen). Methods: This was a retrospective real-world comparative effectiveness study comparing two vaccination strategies (use Ad26.COV2.S versus use BNT162b) among adult patients dialyzing at a large dialysis organization. Patients receiving Ad26. COV2.S were matched 1:1 to those initiating a BNT162b2 series based on age, race, US state of residence, calendar week of first vaccine receipt, and prior history of COVID-19. Follow-up time began the day after the first vaccine dose. The outcome of interest was the comparative rate of polymerase chain reaction-confirmed SARS-CoV-2 infections considered over 3 follow-up intervals: days 1-21, 22-42, and ≥ 43 post vaccination. Results: There were 2683 matched pairs of patients who received a first dose of each vaccine. During days 1-21, the incidence rate was 1.26 infections per 1000 patient-weeks (pt-wks) among BNT162b2 recipients and 1.26 among Ad26.COV2.S recipients (incident rate difference [IRD]: 0.00;95% confidence interval [CI]: -1.10, 1.10). During days 22-42, the incidence rate was 0.93 infections per 1000 pt-wks among BNT162b2 recipients and 0.40 among Ad26.COV2.S recipients (IRD: -0.50;95% CI: -1.40, 0.30). After day 43, the incidence rate was 0.50 infections per 1000 pt-wks among BNT162b2 recipients and 0.50 among Ad26.COV2.S recipients (IRD: 0.00;95% CI: -0.8, 0.8). Results were nearly identical when considering only patients without a prior history of COVID-19. Conclusions: In a large contemporary cohort of dialysis patients, a use Ad26. COV2.S strategy versus a use BNT162b2 strategy would be expected to yield no difference in additional cases of SARS-CoV-2 infections. Given similar effectiveness, vaccine allocation should be based on availability and logistical considerations.
ABSTRACT
Background: The coronavirus disease 2019 (COVID-19) pandemic is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Assessment of newly developed anti-SARS-CoV-2 antibody tests in hemodialysis patients is needed. Methods: As part of a quality improvement (QI) initiative, nasopharyngeal swabs and predialysis blood samples were collected on the same day from adults receiving routine dialysis care at clinics managed by a large dialysis organization in the Miami, Florida, region (April 23-30, 2020). Polymerase chain reaction (PCR) tests for SARS-CoV-2 (Fulgent Genetics, Temple City, California) and chemiluminescence immunoassays (Diazyme Laboratories, Inc, Poway, California) were performed according to manufacturer protocols. For antibody tests (IgM and IgG), a reading of >;1 arbitrary unit/ mL was scored as positive. Results: Of 715 participants in the QI initiative, 38 had symptoms consistent with COVID-19 prior to or during the initiative. Among these, COVID-19 was confirmed in 14 and ruled out in 20, with 4 being inconclusive. Among the 34 patients with known COVID-19 status, the sensitivity and specificity of the antibody test were 57.1% and 85.0%, respectively, when both IgM and IgG were considered. The remaining 677 patients had no record of symptoms consistent with COVID-19 or any known exposure. Of these, 38 (5.6%) tested positive for anti-SARS-CoV-2 antibodies;none of the antibody-positive patients with available PCR results (N=33) tested positive for SARS-CoV-2. Conclusions: The operational characteristics of the laboratory-based antibody test make it sufficient to rule in, but not rule out, SARS-CoV-2 infection in the appropriate clinical circumstance. A substantial proportion of dialysis patients may have had asymptomatic SARS-CoV-2 infection.