SARS-CoV-2 S1-RBD IgG titers before and after third heterologous booster vaccination with Moderna COVID-19 vaccine in hemodialysis patients

Abstract

We measured Abbottʼs S1-RBD IgG antibody titers before and after the third dose of Modernaʼs COVID-19 vaccine in hemodialysis (HD) patients, and examined factors affecting antibody titers. We used Pfizerʼs BNT162b2 (Pfizer) until the second vaccination, and Modernaʼs mRNA-1273 (Moderna) for the third vaccination 6 months after the second vaccination. Antibody titers increased markedly from a median of 275 (149-571) AU/mL before vaccination to 29,737 (14,984-46,185) AU/mL (108.1-fold) one month after vaccination. Multiple regression analysis showed that post-immunization antibody titers were lower in steroid-naive patients, and were also lower in patients with a lower BMI with the exception of those with a BMI of 30 or higher. The results suggest that hemodialysis patients who show emaciation or take steroids need to take more care regarding infection protection after vaccination.