Humoral response to SARS-CoV-2 vaccination in haemodialysis patients and a matched cohort.

Objectives: SARS-CoV-2 vaccination is a crucial intervention for infection control; however, the immune response to vaccination in dialysis patients has been reported to be moderate compared with healthy adults. There are few studies available on humoral response in immunised dialysis patients compared with well-matched control group, we conducted a prospective cohort study measuring SARS-CoV-2 antibody titres in Fukushima Prefecture, Japan since September 2021.

Participants: We compared the titres of both anti-SARS-CoV-2 S1 IgG and neutralising antibodies of 65 haemodialysis patients (dialysis group) with 500 residents in Soma, Fukushima (control group).

Methods: Coarsened exact matching was used to balance sex, age and days from the second dose between dialysis and control groups.

Results: Significant differences in the titres of anti-SARS-CoV-2 S1 IgG and neutralising antibodies were observed between the dialysis and control groups; anti-SARS-CoV-2 S1 IgG: 168.35 (4.48-1074.29) AU/mL and 269.81 (4.72-945.96) AU/mL in dialysis and control groups, p=0.02, neutralising antibodies: 35.77 (2.94-826.06) AU/mL and 62.22 (0.00-535.57) AU/mL, p=0.007, respectively).

Conclusions: We observed significantly reduced anti-SARS-CoV-2 S1 antibody and neutralising antibodies in haemodialysis patients compared with cohorts matched for duration after vaccination. Patients receiving haemodialysis should be carefully monitored for immunological responses to the vaccination and COVID-19 infection.