First-of-Its-Kind Rapid COVID-19 Test Detects Neutralizing Antibodies with 99-100% Specificity and 95-100% Sensitivity Within an Hour

A first-of-its-kind rapid COVID-19 test can detect neutralizing antibodies with high specificity and sensitivity within an hour and is capable of differentiating antibody responses from other known human coronaviruses.

This unique and rapid SARS-CoV-2 surrogate virus neutralization test (sVNT) has been developed by the Duke-NUS Medical School (Singapore), in collaboration with National Centre for Infectious Diseases (NCID), Agency for Science, Technology and Research (A*STAR)’s Institute of Molecular and Cell Biology (IMCB) Singapore, and GenScript Biotech. The test could provide a much-needed boost to current COVID-19 investigations to determine infection rate, herd immunity, predicted humoral protection, and vaccine efficacy during clinical trials.

The sVNT is capable of detecting the functional neutralizing antibodies (NAbs) that can block the binding of the coronavirus spike protein to the angiotensin-converting enzyme 2 (ACE2) host receptor, which mimics the virus-host interaction. Scientists in Singapore and China validated the test across two patient cohorts, with a sample size of 250 from China and 375 from Singapore, achieving 99-100% specificity and 95-100% sensitivity. The sVNT can also measure NAbs from different animals in a species-independent manner. It can therefore be a powerful tool to investigate the role of animals in the transmission of COVID-19 from natural reservoirs to intermediate hosts. The sVNT kit is commercialized by GenScript and offered worldwide under the brand cPass for research use only. GenScript has also filed for Emergency Use Authorization with the US Food and Drug Administration and this filing is currently under review.

“The sVNT kit can detect functional NAbs in an hour and differentiate them with binding antibodies (BAbs), without the need for live virus or a biocontainment facility. It also has the ability to detect total receptor binding domain (RBD)-targeting neutralizing antibodies in patient samples, in contrast to most SARS-CoV-2 antibody tests published or marketed, which are isotype-specific. This makes the sVNT accessible to the broader community for both research and clinical applications,” said Professor Wang Linfa, Director of Duke-NUS’ Emerging Infectious Diseases program.

“It is an increasingly critical clinical question about what proportion of patients with COVID-19 develop antibodies to COVID-19, how long it lasts, and whether antibodies protect patients from re-infection. Neutralizing antibody is the gold-standard serological platform to determine this. Unfortunately, the conventional virus neutralization assay is laborious, time-consuming and requires Biosafety Level 3 for COVID-19. The sVNT developed by Professor Wang, in collaboration with the national COVID-19 PROTECT study, makes it accessible to all hospital laboratories, and is a great advance in COVID-19 serological assays,” said Associate Professor David Lye, Director, Infectious Disease Research and Training Office (IDRTO), and Senior Consultant, NCID.

“This is great news for scientists researching herd immunity and vaccine efficacy as they will now have access to this innovative research tool to accurately determine the level of neutralizing antibodies in a population. We believe the test will shed new light on the current plaguing mysteries of COVID-19,” said David Martz, Vice President of New Product Management, Life Sciences Group, at GenScript.

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Duke-NUS Medical School