Study Finds Significant Variability in Accuracy of Marketed COVID-19 Antibody Tests

A new study by a group of international researchers has found significant variability in the accuracy of currently available COVID-19 antibody tests.

Serological diagnostic tests are being increasingly used to provide a broader understanding of COVID-19 incidence and to assess immunity status in the population. The urgent need for the development of serological diagnostic tests in response to the COVID-19 outbreak has compelled regulatory bodies to implement emergency use authorization programs to expedite the commercialization process of these tests. In light of this, independent and robust post-market evaluations of COVID-19 serological tests are needed to confirm manufacturers’ performance claims.

However, there are discrepancies between claimed and actual performance data for serological diagnostic tests on the market. In the study 'COVID-19 Serological Tests: How Well Do They Actually Perform?', the researchers conducted a review of independent studies evaluating the performance of SARS-CoV-2 serological tests. The researchers included studies that reported sensitivity and specificity, stage of disease (early, intermediate, or late), the test format (CLIA, ELISA, RDT), and antibody target (IgA, IgG, IgM, or IgG + IgM). If available, the SARS-CoV-2 antigens used for antibody detection were recorded. The studies that did not specify the disease stage of test samples were grouped under the “overall” category and assessed separately. In total, the researchers reviewed performance data on five serological CLIA tests, 15 serological ELISA tests, and 42 serological RDTs currently on the market.

They found significant variability in the accuracy of marketed tests and highlight several lab-based and point-of-care rapid serological tests with high levels of performance. The findings of this review highlight the need for ongoing independent evaluations of commercialized COVID-19 diagnostic tests.

"No single assay can be used for all diagnostic use cases in the COVID-19 response for a country. What works well in one setting may be inappropriate or not accessible for another. As such, access to information on test performance, that is generated independently, greatly assists countries in informed decision-making," said study co-author Robyn Meurant, Executive Director of Health Sciences for NSF International.

"Antibody testing is important to understand the extent of exposure for COVID-19 so it can be effectively monitored and treated. It is important for regional and national governments to continue their coordinated efforts to independently validate antibody test performance and also partner with industry to scale up manufacturing and production capacity," said Ali Ardakani, Founder & Managing Director at Novateur Ventures.