Introduction: Hemodialysis patients as well as healthcare workers are considered to be in a high-risk category for SARS-CoV-2 infection and a priority for vaccination.
Methods: In a single-center out-patient hemodialysis unit, 46 healthcare workers and 216 patients were vaccinated simultaneously with BNT162b2 (BioNTech-Pfizer) vaccine. They received two doses, 21 days apart. The primary objectives were to evaluate the safety and efficacy of the vaccine.
Findings: There were no major adverse events in either group. Lymphadenopathy was reported by some health workers. All (100%) individuals in the healthcare workers group developed a positive antibody response (anti-S IgG) after the second dose compared with 91.7% of patients. Among patients there was a significant negative correlation between anti-S levels and age after both, the first dose (R= -0.176, p=0.01) and the second dose (R= -0.193, p=0.005); there was also a significant negative correlation between anti-S and Charlson Comorbidity Index adjusted for age after both, the first dose (R= -0.150, p=0.028) and the second dose (R= -0.163, p=0.018). Finally, a negative correlation between anti-S and Body Mass Index was found after the first dose (R= -0.140, p=0.04). No correlations were found with dialysis vintage, Kt/V, or diabetes.
Conclusions: Following vaccination, patients had a significantly lower anti-S response than healthcare workers. Age, Charlson Comorbidity Index and Body Mass Index negatively impacted the humoral response. However, with more than 91% response we believe that vaccination can be recommended strongly in the hemodialysis population.