Monitoring strategy of COVID-19 vaccination in dialysis patients based on a multiplex immunodot method: The CovidDial study

Introduction: COVID-19 vaccine was demonstrated to be effective in dialysis patients, but boosters are mandatory due to a rapid waning of anti-spike antibodies. A vaccination strategy based on immunologic response might be useful to maintain a favorable risk-benefit balance in this vulnerable population. Methods: CoviDial is an observational prospective study enrolling 121 dialysis patients to receive a 3-dose mRNA-1273 vaccine according to a uniform schedule. At baseline, months 1, 3, 6, 9, and 12, anti-spike antibodies against four epitopes (S1, S2, ECD-S1 + S2, RBD) were monitored with a multiplex immunodot enzymatic assay. Potential correlation between initial serologic response and subsequent COVID-19 infection was then assessed. Results: Overall, 96.2% and 96.8% of patients had anti-RBD antibodies at 3 and 12 months, respectively. All antibodies titers significantly decreased at month 6 compared to month 3. Booster vaccine induced a robust serologic response at month 9, but with a waning 3 months later, particularly for anti-S2 (37.2 +/- 3.3 vs. 61.3 +/- 3.0, p < 0.0001) and anti-S1 + S2 antibodies (68.4 +/- 3.3 vs. 88.4 +/- 2.3, p = 0.0015). Fifteen patients were later tested positive for SARS-CoV-2. At month 3, mean titers of anti-RBD, anti-S1 + S2, and anti-S2 antibodies were lower in the subsequent SARS-CoV-2 infected cohort (71.57 +/- 9.01 vs. 85.79 +/- 2.61, p = 0.0131; 41.07 +/- 7.96 vs. 61.68 +/- 3.56, p = 0.0237; 13.79 +/- 5.03 vs. 39.70 +/- 3.86, p = 0.0096; respectively). Conclusion: Three doses of mRNA-1273 vaccine induce a robust but time-limited immunologic response in dialysis patients. Lower anti-spike antibodies titers after initial vaccination are associated with a higher risk to subsequently contract SARS-CoV-2, even beyond 6 months.

Automated summary

COVID-19 vaccine induces an immunologic response in dialysis patients, but boosters are necessary due to rapid waning of antibodies. Lower antibody titers after initial vaccination are associated with a higher risk of subsequent SARS-CoV-2 infection.