ABSTRACT
Background: This project aims to analyze the proportion of patients who did not develop antibodies following COVID-19 vaccination and to ensure that the immune stimulation secondary to the vaccine is not associated with clinical rejection and DSA development. Methods: Samples collected from COVID-19 vaccinated kidney transplant recipients from 3/1/21-4/26/21 were tested for DSA and COVID-19 antibodies using a multi-antigen detection Luminex platform (BioRad). The following were tested: receptor binding domain IgG, spike 1 IgG, spike 2 IgG, nucleocapsid IgG. Results: 94 patients were included in this study. 57% had no antibodies post second dose of COVID-19 vaccination. This number decreased to 52% when looking at samples collected >2 weeks after the final vaccine dose. Of all positive patients, 19% showed evidence of previous COVID-19 infection based on nucleocapsid positivity, which if excluded from the cohort analysis, lead to a higher rate of patients not responding to the vaccine. We did not observe a correlation between antibody positivity and demographics or clinical characteristics. Only 2 patients developed new DSA post-vaccination(avg MFI 1600). No episodes of clinical rejection were noted. 10 patients provided multiple samples, of which 5 had positive antibodies with an average decrease of 17 U/mL for S1 IgG per week. Conclusions: When excluding patients previously infected with COVID-19, the rate of positive antibody formation post vaccine is 35%. More research needs to be done to understand the correlation of antibody response and protection against COVID-19 infection.