SARS-CoV-2 Serology Testing in the Setting of Vaccination

Siemens Healthineers Position

To enable an effective vaccination strategy, we advocate for the use of accessible, automated, high-throughput SARS-CoV-2 serology testing to help confirm efficacy and promote public health. Siemens Healthineers formulated a position paper based on input from experts in the infectious disease, immunology and vaccine development fields and the currently available body of literature. 

Serology tests can inform vaccination utilization and status of vaccine response at multiple junctures:

  • Data to establish a threshold for protection or immunity
  • Post-vaccination initial response1
  • Duration of vaccination response2

Appropriate characteristics of a serology assay in the assessment of need to vaccinate and vaccine response:

  • Quantitative results
  • Spike protein receptor-binding domain (S1 RBD) neutralizing IgG antibody detection
  • Very high specificity (≥99.5%)

PPP Report on Antibody Testing

A new report from Public Policy Projects (PPP) in the United Kingdom, in partnership with Siemens Healthineers, considers the potential antibody testing holds in increasing the efficiency of the COVID-19 vaccination program, as well as barriers that currently exist. The report recommends public health, NHS personnel, and the industry give consideration to collaborating on new and sustainable diagnostic and monitoring systems post-pandemic.

The report identifies series of key recommendations which include:

  1. Antibody testing should be regarded as an investigational tool, useful for population surveillance and testing those at risk of a sub-optimal vaccine response.
  2. Measuring antibody levels post-vaccination to determine eligibility for a booster vaccination has been proposed as a vaccine-sparing targeted strategy. The appropriateness of this approach needs urgent consideration.
  3. Nations, like the UK, should encourage a global effort, including bodies such as the Centers for Disease Control and Prevention (CDC) and the G7 countries, to work on developing COVID-19 antibody standards as a matter of urgency. 

* Not applicable in the United States.

Neutralization of the SARS-CoV-2 virus with S1-RBD

SARS-CoV-2 serology assays that utilize the receptor-binding domain (RBD) of the S1 spike antigen detect neutralizing antibodies that block the virus entry into cells.3-8 S1-RBD-specific assays are likely to prove advantageous over S1 and whole spike, especially if using a quantitative assay, as neutralizing versus binding antibodies might be expected to be enriched and therefore better correlate to immunity.

The utilization of the S1-RBD is aligned with the multiple vaccines in development that target or include the SARS-CoV-2 S1 RBD, with the goal of producing neutralizing (and therefore likely protective) antibodies in vaccinated subjects.9 The spike protein and particularly the RBD are the most common target of vaccine designs.

Virologist Angela Rasmussen, PhD, presents webinar on SARS-CoV-2 Serology Testing in the Setting of Vaccination

Hear from Dr. Angela Rasmussen, Virologist, on why serology testing is necessary to help inform a long-term vaccination strategy and confirm vaccine effectiveness