Humoral Response to mRNA-1273 SARS-CoV-2 Vaccine in Peritoneal Dialysis Patients: Is Boostering After Six Months Adequate?

Abstract

In dialysis patients the humoral response to anti-SARS-CoV-2 vaccines is attenuated and rapidly declines over time. However, data on the persistence of the immune response in peritoneal dialysis (PD) patients are scarce, particularly after a third (booster) dose with mRNA-1273 vaccine. In this prospective cohort study, we report anti-SARS-CoV-2 antibody levels in PD patients before and after the third dose of mRNA-1273 vaccine. Six months after the second dose, anti-SARS-CoV-2 antibodies were detected in all patients (n = 34). However, within this time period antibodies substantially declined in 31 of 34 patients (4.5-fold, median = 192 BAU/mL, p = 1.27 × 10^-9) and increased in three patients. In accordance with government regulations, a third dose of mRNA-1273 vaccine (50 μg) was given to 27 PD patients 6 months after the second dose which induced a significant increase of anti-SARS-CoV-2 antibody titers (58.6-fold, median = 19405 BAU/mL, p = 1.24 × 10^-29). A mixed model analysis showed that a lower Davies Comorbidity Score and a higher GFR were associated with higher antibody titers (p = 0.03 and p = 0.02). The most common adverse events after the third dose were pain at the injection site (77.8%) and fatigue (51.9%). No hospitalizations were reported. In conclusion, 6 months after the second dose of mRNA-1273 vaccine, anti-SARS-CoV-2 antibodies substantially decreased in PD patients, whereas a well-tolerated third dose induced a robust humoral response. Our data suggest that the administration of a booster dose within a shorter interval than 6 months should be considered in PD patients in order to maintain high anti-SARS-CoV-2 antibody levels and assure protection from severe COVID-19 disease.

Keywords: COVID-19; anti-SARS-CoV-2 antibodies; booster; mRNA-1273 vaccine; peritoneal dialysis; spikevax.

FIGURE 1

Study flowchart of the peritoneal dialysis patient cohort.

FIGURE 2

(A) Anti-SARS-CoV-2 S antibody levels in peritoneal dialysis patients in response to mRNA-1273 vaccine: t1 = 1 month after the first dose (median = 6.62 BAU/mL, IQR 1.57–22.50), t2 = 1 month after the second dose (median = 968 BAU/mL, IQR 422.50–2244.5), t3 = 6 months after the second dose (median = 192 BAU/mL, IQR 84.5–685.0), and t4 = 1 month after the third dose (median = 19,405 BAU/mL, IQR 8,884–25,000). Six months after the second dose antibodies substantially declined and increased significantly after the third dose of mRNA-1273 vaccine. The technical lower and upper limit of detection were 0.4 BAU/mL and 25,000 BAU/mL, respectively. (B) Association of GFR and (C) Davies Comorbidity Score with anti-SARS-CoV-2 S antibody titers in peritoneal dialysis patients in response to mRNA-1273 vaccine 1 month after the first dose (red), 1 month after the second dose (orange), 6 months after the second dose (blue) and 1 month after the third dose (black). A higher GFR and lower Davies comorbidity score are associated with higher antibody titers. This association was particularly evident after the first and second dose, but almost disappeared after the third dose.