SARS-CoV-2 antibody responses in infection-naive or previously infected peritoneal dialysis patients after 2 doses of the BNT162b2 vaccine

Dialysis-associated immune dysfunction makes chronic kidney disease patients both susceptible to severe Coronavirus disease 19 (Covid19) and to a weaker response to vaccination. Previously infected patients are thought to sustain stronger and more durable humoral responses than vaccinated patients. Four months after a two dose-regimen of the Pfizer/BioNTech SARS-CoV-2 mRNA vaccine (BNT162b2), we evaluated the SARS-CoV-2 spike immunoglobin G (IgG-S1) antibody levels in previously infected peritoneal dialysis patients and compared them with infection naïve PD patients. A total of 79 peritoneal dialysis patients were analyzed, of which 11 had a previous history of Covid19. We have verified that the median titer of the IgG-S1 in previously infected patients (14310 AU/mL) was significantly superior to that in infection naïve patients (760,05 AU/mL) (p < 0,001). Previous Covid19 was the only significant predictor of IgG-S1 levels in a multivariate linear regression model (p < 0,001). These results may impact vaccination strategies for peritoneal dialysis patients regarding the future administration of BNT162b2 booster doses. In conclusion, previously infected peritoneal dialysis patients who have completed a two-dose regimen of the BNT162b2 may be well suited without a third, booster dose for longer than infection naïve peritoneal dialysis patients. This strategy could make additional doses available around the world.