Long Term Humoral Immunity Decline in Hemodialysis Patients Following SARS-CoV-2 Vaccination

Abstract

Dialysis patients are extremely vulnerable to SARS-CoV-2 infection with high rates of hospitalization and mortality rates estimated at 20-30%. In January of 2021, the University of Virginia Dialysis Program initiated a program wide vaccination campaign administering Pfizer BioNTech mRNA SARS-CoV-2 (BNT162b2) vaccine. To characterize the time-dependent decline in humoral immunity, we performed 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. Measurements were taken beginning at 2 months post full vaccination through 6 months after full vaccination. Early results showed similar seroconversion rates as prior studies with 88% obtaining positive antibody levels. Those with prior infection obtained the highest antibody levels. Over the ensuing months, patient antibody levels declined at an adjusted average rate of 31% per month. At the conclusion of the study, 40% of patients remaining in the cohort possessed either negative or borderline IgG antibody levels. Projecting future antibody levels based on the slopes of antibody level decay suggests 65% of the cohort will progress to borderline or negative antibody levels at 10 months post full vaccination. In summary, we studied long term vaccine response following vaccination with the BNT162b2 mRNA vaccine in hemodialysis patients. Our data adds to the limited pool of data in this patient population and will help to inform the discussion about vaccine booster needs and frequency.

Dialysis modality, humoral response to vaccine, and SARS‐CoV‐2 infection risk: Comparative prospective evaluation

“…After two doses of BNT162b2, anti‐spike IgG levels in HD patients declined over 6 months, by an average of 31% per month 17 . This decline was more pronounced in older patients and in those receiving immunosuppressive treatment, and resulted in 61%–73% seropositivity rates among HD patients 6 months after vaccination 20–23 . Similarly, patients in the current study who received only two vaccine doses had a marked decrease in antibody titers over a 1‐year follow‐up.…”

“…17 This decline was more pronounced in older patients and in those receiving immunosuppressive treatment, and resulted in 61%-73% seropositivity rates among HD patients 6 months after vaccination. [20][21][22][23] Similarly, patients in the current study who received only two vaccine doses had a marked decrease in antibody titers over a 1-year follow-up. To our knowledge, this study is one of the first to report humoral responses in dialysis patients over a year after the first vaccination.…”

COVID-19 in dialysis: clinical impact, immune response, prevention, and treatment

“…Data on the longevity of the humoral response to vaccination in dialysis patients are rapidly emerging (De Vriese et al, submitted) 74,76,[91][92][93][94][95] (Table 1) and reveal a gradual waning of antibody levels with a rate of decline similar to that in the general population. Not unsurprisingly, more durable responses were observed when the initial titers were higher, e.g.…”

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

“…We previously reported long-term humoral responses to two doses of BNT162b2 in a cohort of hemodialysis patients. 3 Six months after full vaccination, 40% of patients’ anti-spike protein IgG levels were either undetectable or borderline. Here, we report responses to a first booster of the BNT162b2 vaccine.…”

“…Clinical data was obtained as previously described. 3 Of 35 hemodialysis patients in the original cohort, 27 (77.1%) received a third dose of BNT162b2 and 20/27 (74%) had complete data (4 time point measurements): pre-booster (mean of 6 weeks prebooster) and 2, 6 and 11 weeks post-booster. Differences in antibody levels over time were compared non-parametrically using the Friedman test, then tested pairwisely with Bonferroni correction at alpha of < 0.05.…”