Determinants of protective humoral response to mRNA-1273 and BNT162b2 vaccines in peritoneal dialysis patients: a prospective cohort study.

Patients with chronic kidney disease (CKD) on dialysis have a higher mortality rate associated with SARS-CoV-2 infection. Although vaccines are now available, the protective response rates and determinants of humoral response to the vaccine are poorly described in patients on peritoneal dialysis. This was a prospective observational study describing the response rates of detectable and standardized protective antibody titers one month after each mRNA vaccine dose in a cohort of 88 patients on peritoneal dialysis. We found that the vast majority of patients produced protective levels of antibodies (73%) one month after the second vaccine dose. In the multivariate analysis, the single determinant for an adequate humoral response was the weekly Kt/V, a surrogate of dialysis dose. The response rate was higher, but not significantly, with the mRNA-1273 than with the BNT162b2 vaccine one month after the second dose (78.7 vs. 46.2%, respectively, p = 0.02). We found that patients on peritoneal dialysis had a satisfactory humoral response rate, which was much higher than in transplant recipients. PD patients with a poor humoral response, particularly those with a low wKT/V, may benefit from an additional dose of vaccine.