SARS-CoV-2 Booster Effect and Waning Immunity in Hemodialysis Patients

Abstract

Background: Dialysis patients are extremely vulnerable to SARS-CoV-2 infection. We recently reported the results of a prospective cohort study measuring serial monthly semi quantitative IgG antibody levels to the SARS-CoV-2 spike protein receptor binding domain in fully vaccinated in-center hemodialysis patients after receiving the BNT162b2 (Pfizer-BioNTech) mRNA vaccination. Methods: Prospective cohort study measuring the serologic response of hemodialysis patients to a booster dose of BNT162b2 vaccine at an average of 2, 6 and 11 weeks post vaccination. Results: Of 35 hemodialysis patients in the original cohort, 27 (77.1%) received a third dose of BNT162b2. Antibody level significantly increased from pre-booster to 2 weeks post-booster (median (25th, 75th percentile) from 59.94 (29.69, 177.8) to 6216 (3806, 11730)), an average increase of 112 fold. Antibody levels dropped to a median of 2654 BAU/mL (1650, 8340) 6 weeks post-booster and to a median of 1444 BAU/mL (1102, 2020) between weeks 6 and 11 post-booster. Antibody levels at 11 weeks remained an average of 40 fold higher than pre-booster levels. Overall, antibody levels declined 47% month to month post-booster. Nine (33%) patients had negative or borderline detectable antibody levels pre-booster and 8 of 9 developed positive (>35.2 BAU/mL) antibody levels post-booster. Those with prior infection had a lower proportional increase in antibody level (51 fold) compared with the median change in COVID naive patients (144 fold) from pre-booster to 2 weeks post-booster. Conclusions: Our data demonstrates that hemodialysis patients obtain a robust humoral response from a third dose of the BNT162b2 vaccine although antibody levels wane over time.

Humoral immunity trends in a hemodialysis cohort following SARS‐CoV‐2 mRNA booster: A cohort study

“…We recently reported the initial results of antibody levels in these patients up to 11 weeks after boosting 23 . Interestingly, immediately following this, we observed a spike in antibody levels in a large proportion of our patients.…”

“…We followed a cohort of these dialysis patients and reported their long‐term humoral responses to two doses of BNT162b2 for 6 months after full vaccination 6 . A subset of these patients received a third dose of BNT162b2 and their short‐term antibody response was reported 23 . Here, we complete the three‐part series to fully characterize the natural history of antibody levels in hemodialysis patients following mRNA‐based vaccine boosters.…”