Short-term antibody response and tolerability of one dose of BNT162b2 vaccine in patients receiving hemodialysis

Goupil, R.; Benlarbi, M.; Beaubien-Souligny, W.; Nadeau-Fredette, A.-C.; Debashree, C.; Goyette, G.; Lamarche, C.; Finzi, A.; Suri, R. S.

Background: Patients with end-stage kidney disease receiving in-center hemodialysis are at high risk of exposed to, and dying from, SARS-CoV-2. As impairments in both humoral and cellular immunity are common in this population, their response to vaccination against SARS-CoV-2 is uncertain. Methods: We have followed in-center hemodialysis patients in the Reseau Renal Quebecois since March 2020 with serial PCRs for COVID-19 and clinical outcomes. Plasma samples were taken from 58 patients from one center before, and 4 weeks after, vaccination with one dose of the BNT162b2 mRNA vaccine. Anti-RBD (region binding domain of the SARS-CoV-2 Spike protein) IgG levels were measured using ELISA and compared to levels in 32 health care worker (HCW) controls, as well as levels in convalescent plasma taken from 12 hemodialysis patients 4-12 weeks after COVID-19 infection. Patients were stratified based on evidence of previous infection with COVID-19 (positive PCR or antiRBD detectable at baseline). Results: Compared with health-care workers, hemodialysis patients without prior COVID-19 exhibited significantly lower anti-RBD IgG levels 4 weeks after vaccination (p=0.0007). Anti-RBD IgG was non-detectable in 1/16 (6%) of HCWs, and 25/46 (54%) of dialysis patients (p=0.0008). In dialysis patients previously infected with COVID-19, mean anti-RBD levels were significantly lower than their HCW controls (p=0.0031), but not signficantly different than those in convalescent plasma of recently infected dialysis patients (p=NS). No patients reported any symptoms 7 days after vaccination on a standardized questionnaire. Conclusion: The BNT162b2 vaccine was well-tolerated in hemodialysis patients, but failed to elicit a humoral immune response in >50% patients by 4 weeks. Whether these patients develop antibodies or T-cell responses after prolonged observation requires further study. Until then, we recommend that rigorous infection prevention and control measures in the dialysis unit and outside of it be continued to prevent SARS-CoV-2 infection in this susceptible population.