Safety and Tolerability of the BNT162b2 mRNA COVID-19 Vaccine in Dialyzed Patients. COViNEPH Project.

Background and Objectives: The Pfizer-BioNTech (BNT162b2) COVID-19 mRNA vaccine has demonstrated excellent efficacy and safety in phase 3 trials. However, no dialyzed patients were included, and therefore safety data for this patient group is lacking. The aim of the study was to assess the safety and tolerances of vaccinations with BNT162b2 performed in chronically dialyzed patients. Materials and Methods: We performed a prospective cohort study including a group of 190 dialyzed patients (65% male) at median age 68.0 (55-74) years. 169 (89.0%) patients were treated with hemodialysis and 21 (11.0%) with peritoneal dialysis. The control group consisted of 160 people (61% male) without chronic kidney disease at median age 63 (range 53-77) years. Both groups were vaccinated with BNT162b2 with a 21-day interval between the first and the second dose. Solicited local and systemic reactogenicity, unsolicited adverse events and antipyretic and pain medication use were assessed with a standardized questionnaire. The toxicity grading scales were derived from the FDA Center for Biologics Evaluation and Research guidelines. Results: 59.8% (dose 1), 61.4% (dose 2) and 15.9% (dose 1), 29.4% (dose 2) dialyzed patients reported at least one local and one systemic reaction respectively within seven days after the vaccination. Many local and systemic solicited reactions were observed less frequently in dialyzed patients than in the age and sex matched control group and much less frequently than reported in the pivotal study. They were mostly mild to moderate, short-lived, and more frequently reported in younger individuals and women. No related unsolicited adverse events were observed. Conclusions: We have shown here that BNT162b2, an mRNA vaccine from Pfizer-BioNTech against SARS-COV-2 is safe and well-tolerated by dialyzed patients. The results can be useful for the nephrological community to resolve patients' doubts and reduce their vaccine hesitancy.