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

Abstract

AbstractIntroductionCOVID‐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.MethodsCoviDial 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.ResultsOverall, 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).ConclusionThree 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.