COVID-19 outbreak in vaccinated patients from a haemodialysis unit: antibody titres as a marker of protection from infection

Nephrol Dial Transplant. 2022 Jun 23;37(7):1357-1365. doi: 10.1093/ndt/gfac016.

Abstract

Background: Patients on maintenance haemodialysis (HD) have an increased risk of severe coronavirus disease 2019 (COVID-19) and a reduced response to vaccines. Data are needed to identify immune correlates of protection in this population.

Methods: Following a COVID-19 outbreak among vaccinated patients in a HD unit, clinical data and serological response to BNT162b2 vaccine were retrospectively recorded.

Results: Among 53 patients present in the dialysis room, 14 were infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) alpha variant (COVID_Pos) and 39 were not. Compared with uninfected patients, COVID_Pos patients more frequently had additional causes of immunosuppression (50% versus 21%; P = .046) and were more often scheduled on the Monday-Wednesday-Friday (MWF) shift (86% versus 39%; P = .002). Moreover, COVID_Pos had lower anti-spike (S) immunoglobulin G (IgG) titres than uninfected patients {median 24 BAU/mL [interquartile range (IQR) 3-1163] versus 435 [99-2555]; P = .001} and lower neutralization titres [median 108 (IQR 17-224) versus 2483 (481-43 908); P = .007]. Anti-S and neutralization antibody titres are correlated (r = 0.92, P < .001). In multivariable analysis, an MWF schedule {odds ratio [OR] 10.74 [95% confidence interval (CI) 1.9-93.5], P = .014} and anti-S IgG titres 1 month before the outbreak [<205 BAU/mL: OR 0.046 (95% CI 0.002-0.29), P = .006] were independently associated with COVID-19 infection. None of the patients with anti-S IgG >284 BAU/mL got infected. Ten of 14 COVID_Pos patients were treated with casirivimab and imdevimab. No patient developed severe disease.

Conclusions: Anti-S IgG titre measured prior to exposure correlates to protection from SARS-CoV-2 infection in HD patients. BNT162b2 vaccination alone or in combination with monoclonal antibodies prevented severe COVID-19.

Keywords: BNT162b2 mRNA vaccination; COVID-19 outbreak; haemodialysis; humoral response; monoclonal antibodies.

MeSH terms

  • Antibodies, Monoclonal, Humanized
  • Antibodies, Viral
  • BNT162 Vaccine
  • COVID-19* / epidemiology
  • COVID-19* / prevention & control
  • Disease Outbreaks
  • Hemodialysis Units, Hospital
  • Humans
  • Immunoglobulin G
  • Renal Dialysis
  • Retrospective Studies
  • SARS-CoV-2
  • Viral Vaccines*

Substances

  • Antibodies, Monoclonal, Humanized
  • Antibodies, Viral
  • Immunoglobulin G
  • Viral Vaccines
  • imdevimab
  • casirivimab
  • BNT162 Vaccine

Supplementary concepts

  • SARS-CoV-2 variants