Study suggests GenScript’s cPass™ test is faster, better and safer than traditional tests
PISCATAWAY, N.J., July 23, 2020 /PRNewswire/ — GenScript Biotech Corp., the world’s leading research reagent provider, today announced that clinical data published in Nature Biotechnology on a new method for detecting COVID-19 neutralizing antibodies in serum indicates it is safer, faster, easier and more effective than traditional virus-based assays, with comparable specificity. The article1 titled “A SARS-CoV-2 surrogate virus neutralization test based on antibody-mediated blockage of ACE2–spike protein–protein interaction,” was authored by Professor Lin-fa Wang, Director of Emerging Infectious Diseases at Duke University Medical School of Singapore, a world leading research scientist in virus infectious diseases, in collaboration GenScript, which is commercializing the technology globally as the cPass™ test.
The new cPass™ test is based on an ELISA (enzyme-linked immunosuppressant assay) format, a powerful method of antibody detection that has the potential to be highly scalable and much more suitable for screening large populations compared with traditional live virus neutralization assays. The testing strategy was validated in two COVID-19 patient cohorts in Singapore and China (with a sample size of 375 and 250, respectively). The study directly compared the clinical performance between the cell- and virus-based detection test (cVNT) and the and surrogate virus neutralization test (sVNT), or cPass, with results showing that the cPass test was able to detect neutralizing antibodies from patients with 95%-100% sensitivity and 99.93% specificity.
The cPass™ SARS-CoV-2 Neutralization Antibody Detection Kit is currently under review for Emergency Use Authorization (EUA) with the US Food and Drug Administration, is CE marked for use in the European Union, and has received provisional authorization by the Health Sciences Authority (HSA) in Singapore.
Since the beginning of the epidemic, the research community has been struggling to find an effective and convenient method for detecting neutralizing antibodies. The well-established approach to measuring neutralizing antibodies is known as the “Conventional Virus Neutralization Test (cVNT)” and must be performed in a biosafety containment facility staffed with highly specialized personnel, as it requires the handling of live virus/cells. Often results for the cVNT can only be realized within several days. Moreover, due to the unpredictable nature of live virus and cells and the use of visual evaluation, these tests are difficult to standardize, meaning that results from different facilities cannot be compared, even if performed using the same protocol. Unlike the cVNT, the “Surrogate Virus Neutralization test” (sVNT) method used in cPass kit can detect much faster (~1hr) the presence of neutralizing antibodies and does not require the use of live virus and biosafety containment, making it broadly available and much more consistent between different batches and facilities.
“We are very pleased that Prof. Wang’s work has come to fruition. The work described in this paper not only demonstrates for the first time that sVNT can very quickly detect neutralizing antibodies in hundreds of clinical samples but also provides a key advantage over regular serology kits in its ability to detect these antibodies in an isotype and species-independent manner,” said David Martz, vice president of new product management in Life Science Group at GenScript.
Available immunoglobulin-based (IgG, IgM or IgA) ELISA tests on the market detect antibodies that bind to virus proteins and cannot distinguish between neutralizing and binding antibodies. In contrast, the cPass test is functionally different and is specifically designed to detect antibodies with neutralization function.
The relationship between antibodies and immunity against COVID-19 has been extensively researched and reported. A recent CDC report2 found that positive serological ELISA results may not correlate well with the virus neutralization assays. In this study, among the 228 participants who tested positive using ELISA antibody tests, only 135 were positive in a virus microneutralization test, a cell-based assay that indicates the presence of neutralizing antibodies, showing only a 59.2% correlation. In addition, serological surveys in both China and Spain suggest that there may be difference in the longevity of the binding and neutralizing antibodies, raising a lot of questions about using binding antibody response to determine the ability to prevent re-infection.
These surveys utilized tests available on the market that detect the presence of total binding antibodies but cannot specifically determine the presence of neutralizing antibodies. Prof. Wang’s study performed on two COVID-19 patient cohorts reported that even though patients exhibited a low level of IgG and IgM antibodies, the sVNT assay still detected a significant level of neutralizing activity. Additionally, results obtained from two SARS serum panels, showed that neutralizing antibodies were detectable 17 years after initial infection, which is extremely promising news for recovered COVID-19 patients since these two viruses belong to the same family known as the Betacoronavirus genus.
“It is great news for scientists researching herd immunity and vaccine efficacy, as now they will have access to this innovative research tool to study the presence of neutralizing antibodies in a population. We believe the cPass™ test will help shed new light on the current plaguing mysteries of COVID-19,” added Martz.
- Wang, LF. et al. “A SARS-CoV-2 surrogate virus neutralization test based on antibody-mediated blockage of ACE2–spike protein–protein interaction”, Nature Biotechnology, July 2020.
- Payne D.C. et al. “SARS-CoV-2 Infections and Serologic Responses from a Sample of U.S. Navy Service Members – USS Theodore Roosevelt” April 2020. MMWR. Morb. Mortal. Wkly. Rep. (2020).
About GenScript Biotech Corporation
GenScript Biotech Corporation (Stock Code: 1548.HK) is a global biotechnology group. Based on its leading gene synthesis technology, GenScript has developed four major platforms including the global cell therapy platform, the biologics contract development and manufacturing organization (CDMO) platform, the contract research organization (CRO) platform and the industrial synthesis product platform.
GenScript was founded in New Jersey, US in 2002 and listed on the Hong Kong Stock Exchange in 2015. GenScript’s business operation spans over 100 countries and regions worldwide, with legal entities located in the U.S., Mainland China, Hong Kong, Japan, Singapore, Netherlands and Ireland. GenScript has provided premium, convenient, and reliable products and services for over 100,000 customers.
GenScript has a number of intellectual property rights and technical secrets, including more than 100 patents and over 270 patent applications. As of December 31, 2019, GenScript’s products and services have been cited by 42,200 peer-reviewed journal articles worldwide.
For more information visit www.genscript.com.
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