Real-world effectiveness and immunogenicity of BNT162B2 in dialysis patients

Background: mRNA-1273 (Moderna) is a SARS-CoV-2 vaccine that received an emergency use authorization from the US Food and Drug Administration. Clinical trials in the general population demonstrated that mRNA-1273 reduced risk of COVID-19 by 94.5%, however, dialysis patients were not represented in these trials. Here, we estimated the effectiveness and SARS-CoV-2 antibody response among real-world dialysis patients who were vaccinated with mRNA-1273. Methods: Patients included in this analysis were adults dialyzing at a large dialysis organization. For the effectiveness analysis, patients who began an mRNA-1273 vaccination series (January-March 2021) were matched (with replacement) to up to 3 previously unvaccinated controls based on age, diabetes status, sex, race, body mass index, date of first vaccine, US state of residence, and prior known COVID-19 diagnosis. Vaccine effectiveness was estimated by calculating the hazard ratio (HR) for time to polymerase chain reaction confirmed infection between vaccinated and unvaccinated patients over 3 follow-up intervals: days 1-21, 22-42, and ≥43 after first dose of vaccine. Immunogenicity was measured in a subset of consented patients who completed the full, 2-dose mRNA-1273 vaccination schedule. Blood samples were collected approximately 28 days after the second dose of mRNA-1273, and indirect chemiluminescence immunoassays were used to measure immunoglobulin G (IgG) antibodies against SARS-CoV-2. Samples with a reading of >1 arbitrary unit (AU) were considered IgG+. Results: We identified 23,037 patients who received mRNA-1273 and were matched to 64,243 unvaccinated controls. The HRs and 95% confidence intervals (CI) were 0.96 (0.79, 1.16), 0.51 (0.34, 0.75), and 0.27 (0.17, 0.42) during 1-21, 22-42, and ≥43 days postvaccination, respectively. Among the 329 patients with postvaccination antibody measurements, 96.0% (95% CI: 93.3%-97.9%) were IgG+ (median: 100.5 AU of IgG). Conclusions: Our results indicate that mRNA-1273 is effective in preventing SARSCoV-2 infection in dialysis patients. Moreover, antibodies to SARS-CoV-2 were detected in nearly all patients vaccinated with mRNA-1273 in whom antibodies were measured.