Although the majority of patients on maintenance dialysis showed an initial seroresponse to SARS-CoV-2 immunization, the persistence of the antibody reaction was unknown. The seroresponse was assessed by researchers over time in the investigation. The retrospective cohort analysis included patients on maintenance dialysis from a midsize national dialysis provider who got the full SARS-CoV-2 vaccine series and had at least one antibody titer tested after full immunization. Following immunization, IgG spike antibodies (anti-spike IgG) titers were measured monthly using conventional laboratory testing; the semiquantitative technique revealed a range of 0 to 20 Index. Descriptive studies examined coronavirus disease 2019 (COVID-19) and vaccination type trends throughout time. Time-to-event analyses looked at the consequences of losing seroresponse (anti-spike IgG 1 Index or COVID-19 development). 

About 1,569 of the 1,870 patients on continuous dialysis had never been exposed to COVID-19. Patients who had never been exposed to COVID-19 reported diminishing titers throughout time. The median (interquartile range) anti-spike IgG titer in 443 BNT162b2 (Pfizer) patients fell from 20 (5.89 to 20) in month 1 following complete immunization to 1.96 (0.60–5.88) by month 6. Anti-spike IgG titer in 778 mRNA-1273 (Moderna) patients decreased from 20 (interquartile range, 20 to 20) in month 1 to 7.99 (2.61 to 20) by month 6. Overall time periods, the 348 receivers of Ad26.COV2.S (Janssen) showed a lower titer response than recipients of an mRNA vaccination. In time-to-event investigations, Ad26.COV2.S and mRNA-1273 recipients had the quickest and longest time to seroresponse loss, respectively. The highest titer achieved during the first 2 months following complete vaccination was related to the duration of the anti-spike IgG seroresponse; patients with anti-spike IgG titers 1–19.99 had a shorter time to loss of seroresponse compared to patients with anti-spike IgG titer 20. (hazard ratio, 15.5; 95% CI, 11.7 to 20.7).

Vaccine-induced seroresponse declined with time in patients on maintenance dialysis, regardless of vaccine type. Early titers following complete immunization were linked to the persistence of seroresponse.