Immunogenicity of SARS-CoV-2 Vaccine in Dialysis (preprint)

ABSTRACT

Abstract Importance Patients receiving maintenance dialysis patients are at high risk for morbidity and mortality from COVID-19. The immunogenicity of SARS-CoV-2 mRNA vaccines is unknown in this vulnerable population where immune compromise is common. Objective: To determine seroresponse to vaccination against SARS-CoV-2 utilizing mRNA vaccines among patients receiving maintenance dialysis. Design: Retrospective observational study. Setting: Dialysis Clinic, Inc. (DCI) outpatient dialysis clinics in the United States. Participants: All patients receiving maintenance dialysis that received two doses of SARS-CoV-2 mRNA vaccines with SARS-CoV-2 spike-antibody test results drawn at least 14 days after the second dose, as documented in the electronic health record through March 18, 2021. Exposure Two doses of BNT162b2/Pfizer or of mRNA-1273/Moderna vaccines administered per manufacturer recommendations. Main Outcomes and Measures: Levels of immunoglobulin-G against the receptor binding domain of the S1 subunit of SARS-CoV-2 spike antigen (seropositive 2 or greater) using FDA-approved semi-quantitative chemiluminescent assay (ADVIA Centaur XP/XPT COV2G). The DCI clinical protocol for in-clinic administration included baseline and follow-up levels although initial administration of the vaccine occurred primarily elsewhere (e.g. long-term care facilities, hospitals, etc.) during the evaluation period. Hence, only post-vaccination antibody levels were reported. Results: Among 186 patients receiving maintenance dialysis from 32 clinics in 8 states tested an average of 23 days after receiving 2 vaccine doses, mean age was 68 years, with 47% women, 21% Black, 26% residents in long-term care facilities and 97% undergoing in-center hemodialysis. Overall seropositive rate was 165/186 (88.7%) with 70% at maximum titer and with no significant difference in seropositivity between BNT162b2/Pfizer (N=148) and mRNA-1273/Moderna (N=18) vaccines (88.1% vs. 94.4%, p=0.42). Among patients with COVID-19 history, seropositive rate was 38/38 (100%) with 97% at maximum titer. Conclusions and Relevance Most patients receiving maintenance dialysis were seropositive after two doses of BNT162b2/Pfizer or mRNA-1273/Moderna vaccine. Early evidence suggests that vaccinated dialysis patients with prior COVID-19 develop robust antibody response. These results support an equitable and aggressive vaccination strategy for all eligible patients receiving maintenance dialysis, regardless of age, sex, race, ethnicity, or disability, to prevent the extremely high morbidity and mortality associated with COVID-19 in this high risk population.