High immunogenicity of a messenger RNA-based vaccine against SARS-CoV-2 in chronic dialysis patients

Background. Patients with chronic kidney disease, dialysis patients and kidney transplant patients are at high risk of developing severe coronavirus disease 2019 (COVID-19). Data regarding the immunogenicity of anti-severe acute respiratory syndrome coronavirus 2 messenger RNA (anti-SARS-CoV-2 mRNA) vaccines in dialysis patients were published recently. We assessed the immunogenicity of anti-SARS-CoV-2 mRNA vaccine in dialysis patients. Patients and methods. One hundred and nine patients on haemodialysis (n=85) or peritoneal dialysis (n=24) have received two injections of 30-mu g doses of BNT162b2 mRNA COVID-19 vaccine (Pfizer-BioNTech) that were administered intramuscularly 28days apart. Those who were still seronegative after the second dose were given a third dose 1 month later. Anti-SARS-CoV-2 antibodies were tested before and after vaccination. Results. Ninety-one out of the 102 patients who had at least a 1-month follow-up after the second (n=97) or the third (n=5) vaccine doses had anti-SARS-CoV-2 antibodies. The seroconversion rate was 88.7% (86 out of 97 patients) among SARS-CoV-2 seronegative patients at the initiation of vaccination. Receiving immunosuppressive therapy was an independent predictive factor for non-response to vaccination. Conclusion. Due to high immunogenicity and safety of mRNA vaccines, we strongly recommend prioritizing a two-dose vaccination of dialysis patients. A third dose can be required in non-responders to two doses. When possible, patients waiting for a kidney transplantation should be offered the vaccine before transplantation.