International Journal of Infectious Diseases (Aug 2021)

Age significantly influences the sensitivity of SARS-CoV-2 rapid antibody assays

  • Natalie Irwin,
  • Lyle Murray,
  • Benjamin Ozynski,
  • Guy A Richards,
  • Graham Paget,
  • Jacqueline Venturas,
  • Ismail Kalla,
  • Nina Diana,
  • Adam Mahomed,
  • Jarrod Zamparini

Journal volume & issue
Vol. 109
pp. 304 – 309

Abstract

Read online

ABSTRACT: BACKGROUND: Point-of-care serological assays are a promising tool in COVID-19 diagnostics but do have limitations. Our study evaluated the sensitivity of five rapid antibody assays and explored factors influencing their sensitivity in detecting SARS-CoV-2-specific IgG and IgM antibodies. METHODS: Finger-prick blood samples from 102 participants, within 2–6 weeks of PCR-confirmed COVID-19 diagnosis, were tested for IgG and IgM using five rapid serological assays. The assay sensitivities were compared, and patient factors evaluated in order to investigate potential associations with assay sensitivity. RESULTS: Sensitivity ranged from 36% to 69% for IgG and 13% to 67% for IgM. Age was the only factor significantly influencing the likelihood of a detectable IgG or IgM response. Individuals aged 40 years and older had an increased likelihood of a detectable IgG or IgM antibody response by rapid antibody assay. CONCLUSION: Rapid serological assays demonstrate significant variability when used in a real-world clinical context. There may be limitations in their use for COVID-19 diagnosis among the young.

Keywords