Real-world effectiveness and immunogenicity of BNT162B2 in dialysis patients

ABSTRACT

Background: BNT162b2 (Pfizer/BioNTech) 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 BNT162b2 reduced risk of COVID-19 by 95%, 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 BNT162b2. Methods: Patients included in this analysis were adults dialyzing at a large dialysis organization. For the effectiveness analysis, patients who began a BNT162b2 vaccination series (January-March 2021) were matched (with replacement) to up to 4 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 2-dose BNT162b2 vaccination schedule. Blood samples were collected approximately 28 days after the second dose of BNT162b2, 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 12,169 patients who received BNT162b2 and were matched to 44,377 unvaccinated controls. The HRs and 95% confidence intervals (CI) were 0.84 (0.68, 1.03), 0.61 (0.40, 0.93), and 0.21 (0.13, 0.35) during 1-21, 22-42, and ≥43 days postvaccination, respectively. Among the 344 patients with postvaccination antibody measurements, 98.0% (95% CI 95.2%-99.2%) were IgG+ (median 63.3 AU of IgG). Conclusions: Our results indicate that BNT162b2 is effective in preventing SARSCoV-2 infection in dialysis patients. Moreover, antibodies to SARS-CoV-2 were detected in nearly all patients vaccinated with BNT162b2 in whom antibodies were measured.