HUMORAL RESPONSE TO THE PFIZER BNT162B2 VACCINE BOOSTER DOSE IN PATIENTS UNDERGOING MAINTENANCE HEMODIALYSIS

Abstract BACKGROUND AND AIMS COVID-19 is associated with increased morbidity and mortality in maintenance hemodialysis (MHD) patients. Recent breakthrough infection in vaccinated people has led some authorities to recommend a booster dose to patient fully vaccinated 5–8 months ago. The recent emergence of the Omicron (B.1.1.529) variant has heightened this issue. We aimed to assess, the humoral response following a booster dose with the BNT162b2 vaccine in MHD patients. METHOD The study included 102 MHD patients vaccinated with 2 doses of the BNT162b2 (Pfizer-BioNTech) vaccine. A third dose (booster) was recommended to all MHD Patients in our center and was given to all patients that opt to receive it, resulting in a booster group and a control group that did not receive the booster. Previous exposure was excluded by testing for the presence of the Anti-Nucleocapsid Antibody (SARS-CoV-2) or positive PCR. We assessed the humoral response before and after the booster dose. RESULTS 98.5% (65/66) subjects in the booster group developed a positive antibody response (472.7 ± 749.5 to 16 336.8 ± 15 397.3 AU/mL) as compared with a sustained decrease in the control group (n = 22, 695.7 ± 642.7 to 383.6 ± 298.6 AU/mL), P < 0.0001 (Figure 1). No significant adverse effects were reported. Prior antibody titers were positively correlated to IgG S1 levels following the booster dose. There was a significant association between malnutrition-inflammation markers and the humoral response. CONCLUSION The vast majority of MHD patients developed a substantial humoral response following the booster dose administration, it was significantly higher than levels previously reported for MHD patients following administration of 2 doses alone. Further studies and observations are needed in order to determine the exact timing and dosing schedule.