Quest Diagnostics has unveiled a new Covid-19 semi-quantitative serology testing service that offers insight into a person’s immune response to prior SARS-CoV-2 infection or Covid-19 vaccination.
Approximately 40% of SARS-CoV-2-infected people do not experience symptoms. Serology tests can detect people who have developed antibodies that could provide protection from future infection and detect those still at risk, the US Food and Drug Administration (FDA) said.
The test service delivers a positive or negative result and a numerical result that could offer the basis for analysing relative changes in antibody blood levels.
Furthermore, it can help in evaluating blood antibody levels produced to structural proteins of the SARS-CoV-2 spike protein.
As vaccines that are currently available in the US have mRNA that encodes the spike protein, the test could show an immune response, resulting from an infection or vaccination.
The company noted that the test cannot distinguish between immune response mounted in response to infection or vaccination.
Quest Diagnostics senior vice-president and chief medical officer Jay Wohlgemuth said: “We believe that SARS CoV-2 semi-quantitative serology testing will be an important clinical tool to assess if an individual has mounted an immune response from recent or prior infection or vaccination.
“These insights may aid clinical management of certain patients at high risk of severe Covid-19 disease or who may be at risk for vaccination such as people with a history of severe vaccine allergy or women who are pregnant.
“Importantly, we also believe semi-quantitative testing will improve public health surveillance as researchers across the US seek to better understand the contributions of vaccination and prior infections on herd immunity.”
Last July, the FDA granted emergency use authorisation (EUA) for specimen pooling with Quest Diagnostics’ Covid-19 diagnostic test.