SARS-CoV-2 IgG Assay<br />

SARS-CoV-2 IgG AssaySecure your community with science and scale

Rapid and accurate antibody testing on a large scale is key to address the challenges of the COVID-19 pandemic. Over time, SARS-CoV-2 IgG antibodies remain the primary antibodies present.

The Siemens Healthineers Atellica IM* and ADVIA Centaur†† SARS-CoV-2 IgG (sCOVG) assays measure neutralizing IgG antibodies to SARS-CoV-2 in the blood to help clinicians assess the level of an individual's immune response over time.

“Being able to measure a patient’s relative level of antibodies in response to a previous SARS-CoV-2 infection may be useful as we continue to learn more about the virus and what the existence of antibodies may mean. There are still many unknowns about what the presence of SARS-CoV-2 antibodies may tell us about potential immunity, but today’s authorizations give us additional tools to evaluate those antibodies as we continue to research and study this virus.”
Tim Stenzel, M.D., Ph.D., Director of the Office of In Vitro Diagnostics and Radiological Health in the FDA’s Center for Devices and Radiological Health (read press release)

COVID19 Detection Phases

We offer the SARS-CoV-2 IgG (sCOVG) assay and the SARS-CoV-2 Total assay* for the qualitative and quantitative detection of neutralizing antibodies to the SARS-CoV-2 virus.†‡

A correlation study using a viral neutralizing test demonstrated a strong relationship between index values from the Atellica® IM and ADVIA Centaur® SARS-CoV-2 Total and SARS-CoV-2 IgG assays and neutralizing antibody titers. This allows clinicians to be able to assess and monitor patients’ neutralizing antibody levels. This strong correlation is critical for potential convalescent donor identification as well as future determination of vaccine response and monitoring post-vaccination neutralizing antibody levels.

Comparison of numerical results will help determine how the immune response develops in an individual and persists over time. The combination of these assays provides a more complete picture of a patient’s serological status for the most accurate results throughout his or her continuum of care.

The Science

We smartly selected the receptor-binding domain (RBD) of the S1 spike antigen to detect neutralizing IgG antibodies to SARS-CoV-2. This selection is aligned with the multiple vaccines that target or include the SARS-CoV-2 S1 RBD used in our assay, with the goal of producing protective antibody.

The Atellica IM* and ADVIA Centaur†† sCOVG assays detect neutralizing antibodies to the S1 RBD antigen. S1 RBD antibodies are relevant to vaccines incorporating this immunodominant region to elicit neutralizing (and therefore likely protective) antibodies in vaccinated subjects.**1 The spike protein and particularly the RBD are the most common target of vaccine designs.


The Atellica IM* and ADVIA Centaur†† assays provide a qualitative (negative/positive) and quantitative (index value) result that enables clinicians to detect the level of neutralizing IgG antibodies in a patient’s blood sample and assess relative changes over time.†‡

A quantitative result is an important step in the global pursuit to establish an individual’s immunity. With this numerical value, clinicians will have a baseline and be better equipped to assess changes of an individual’s immune response to the SARS-CoV-2 virus.

The ADVIA Centaur SARS-CoV-2 IgG (COV2G)* assay has been authorized by the FDA to be used as a test for the qualification of high titer COVID-19 convalescent plasma in the manufacture of COVID-19 convalescent plasma.3 The FDA EUA for the emergency use of COVID-19 convalescent plasma for the treatment of hospitalized patients with COVID-19 issued in August 2020 has been revised to include the ADVIA Centaur COV2G assay, supported by studies conducted through one of our collaboration partners. It was determined that an Index of ≥ 4.8 was the cutoff necessary to qualify convalescent donor plasma for use in donations.

Plasma from recovered or convalescent COVID-19 patients may contain sufficiently high SARS-CoV-2 antibody titers to be able to treat hospitalized patients with COVID-19, early in the course of disease, and those hospitalized with impaired humoral immunity. This EUA authorization and study data provides laboratories the confidence they need to accurately qualify convalescent donor plasma using the ADVIA Centaur COV2G assay. Additionally, we are working to support inclusion of the Atellica IM COV2G* in this EUA. The use of the Atellica IM sCOVG assay* and ADVIA Centaur sCOVG assay†† for this application is also being pursued.