A team of scientists from the Singapore-MIT Alliance for Research and Technology (SMART), MIT’s research enterprise in Singapore, and Nanyang Technological University, Singapore (NTU Singapore) has developed a rapid test kit that can tell whether a person is immune to Covid-19 and its variants based on the antibodies detected in a blood sample.
Unlike ART tests — which look for the presence of viral proteins produced during Covid-19 infection to determine whether a person is infected — the rapid point-of-care test is a serological test that measures the antibodies produced by a patient . It requires a drop of blood and provides results in just 10 minutes, compared with the 24 to 72 hours required for traditional laboratory tests.
The assay detects levels of neutralizing antibodies against SARS-CoV-2 (the virus that causes Covid-19) and its variants such as delta and omicron, and can be easily adapted to new variants and others of interest in the future disease.
Using a paper-based test coated with chemicals that bind to antibodies in a blood sample, the test kit is cheap, fast and 93 percent accurate. It paves the way for personalized vaccination strategies, where people get vaccinated and booster shots only when necessary, based on differences in antibody levels and immune responses.
The findings were published Sept. 7 in the journal microbial spectrum A joint team led by SMART’s Antimicrobial Resistance (AMR) Interdisciplinary Research Group and NTU’s School of Biological Sciences, in collaboration with the National University Hospital (NUH), Singapore, National Center for Infectious Diseases (NCID) and Massachusetts Institute of Technology.
Accurate and rapid serological testing could allow governments and healthcare organizations to efficiently manage limited vaccine resources and address vaccine hesitancy, especially with regard to multiple booster doses.
Vaccination has been an integral part of the public health strategy to tackle the Covid-19 pandemic, with 12.6 billion doses administered in 184 countries as of September 9. The vaccine reduced Covid-19 deaths by 63% within the first year of its rollout, averting an estimated 19.8 million deaths worldwide, according to a World Health Organization (WHO) report.
In Singapore, the Ministry of Health estimated in February 2022 that the Covid-19 vaccine had prevented 8,000 deaths in the 2021 wave of the Delta variant and prevented an estimated 33,000 severe cases and 112,000 hospitalizations.
However, a clinical study by the joint research team shows that the protection provided by currently available vaccines declines steadily over three months, and the decline varies from person to person. The study showed that neutralizing antibody (NAb) responses to wild-type and Delta remained at a median of 91.8% after three months of booster injections, while median neutralizing antibody responses to Beta and Gamma declined to 82.7, while for Omicron, it dropped from 92.9% to 70.7%.
The Case for a Personalized Vaccine Approach
The emergence of novel variants that are much more transmissible than wild-type viruses—such as Delta and Omicron—exacerbates the problem of using mRNA vaccines developed based on wild-type viruses to boost immunity, especially when some current vaccines show reduced Time to protect against these new variants of concern.
In addition, certain population groups remain vaccine hesitant, in which individuals are wary of getting vaccinated or booster shots due to concerns about side effects, further exacerbating the difficulty of adopting a broad vaccination strategy to build herd immunity.
To address vaccine hesitancy and the effectiveness of vaccination against new variants, a personalized vaccination approach that provides booster doses to individuals assessed as being at higher risk, such as healthcare workers and the elderly, may be more effective.
For a personalized approach to be effective, healthcare professionals need to be able to rapidly assess the level of NAb response to a variant at the individual level using an easy-to-use point-of-care test kit in the clinic, hospital, or hospital. Vaccination Center.
“During the course of the pandemic, several large studies have shown that NAb levels are a reliable indicator of protection from infection,” said Hadley Sikes, SMART AMR principal investigator, associate professor of chemical engineering at MIT, and co-corresponding author of the paper. Some populations have a lower tolerance for the risk of infection. The tests we have developed can provide valuable, personalized information on how quickly or slowly a person’s antibody levels are declining, keeping them informed your own health and, if needed, get the necessary booster doses to protect yourself.”
Peter Preiser, co-principal principal investigator of SMART AMR, vice-chancellor for biomedical and life sciences at Nanyang Technological University in Singapore, and co-corresponding author of the paper, added: “Our team’s work in developing the rapid test kit has given us insight into vaccine effectiveness and Valuable insights into lifespan protection.Our research demonstrates that our new test kit can be a powerful tool that enables healthcare organizations to screen people and determine their vaccination needs, especially in response to current and upcoming changes. This will help alleviate some people’s fears that they will be ‘over-vaccinated with a booster’ because the results will tell exactly whether they are well protected against Covid-19.”
In their research paper, the team describe a clinical study of their cellulose pull-down virus neutralization assay (cpVNT), a neutralizing antibody blood test designed to assess individual responses to SARS-CoV-2 The immune protection profile of its variants.
With just a drop of fingertip blood, the test kit can assess an individual’s level of neutralizing antibodies against a specific Covid-19 variant within 10 minutes, making it an efficient, low-cost and easy-to-use tool that enables large-scale – Tested at scale and can be broadly deployed anywhere as part of a personalized vaccination strategy.
The test reveals an individual’s level of neutralizing antibodies, which can then inform when a person should take a booster dose and how cautious they should be about potential transmission before taking it.
It can be administered by laymen with no medical training and does not require any specialized laboratory equipment, paving the way for mass testing of vulnerable populations such as the elderly.
Co-first author and predecessor of the paper Hoi Lok Cheng, postdoctoral fellow at SMART AMR, said: “This is an exciting breakthrough for us and a continuation of our long-term work to develop highly efficient, low-cost and easy-to-use NAb tests to combat the Covid-19 pandemic. As A quantitative test that can detect levels of NAbs specific to key variants such as delta and omicron, cpVNT has provided us with valuable insights into the effectiveness of various vaccines relative to the variant of interest. The test kit will also be Proving to be integral to a more personalized approach to vaccination that will benefit high-risk populations such as the elderly and healthcare workers Individuals from these communities can have their immune protection status regularly assessed via cpVNT to let them know what There may be times when a booster dose may be appropriate or necessary. In addition, the test can be easily adapted to test new SARS-CoV-2 variants that may emerge in the future.”
based on years of research
This research builds on years of work by the SMART team.In a paper published in the Journal of Medicine and Public Health communication medicine, the team laid the foundation for a cellulose-based vertical flow test to detect neutralizing antibodies against SARS-CoV-2.Another paper published in the Journal of Chemical Engineering Bioengineering and Translational Medicine The validity of this test relative to other methods, such as pseudovirus-based virus neutralization test (pVNT) and surrogate virus neutralization test (sVNT), was discussed with good results.
Using clinical samples (both whole blood and plasma) and the WHO international standard and reference panel for anti-SARS-CoV-2 antibodies, the team determined that whole blood tests, such as cpVNT, can be as informative as plasma—only the test. Because plasma- or serum-based tests require laboratory equipment to process the blood sample and collect a larger number of blood samples, cpVNT is more resource efficient and less invasive. The feasibility of cpVNT also demonstrates that neutralizing antibody and point-of-care testing can be successfully performed using this format and protocol — paving the way for further development and innovation of this platform for other diseases.
Further development of the test kit is ongoing to meet the necessary regulatory approvals and manufacturing standards for public use. The team that developed the test at SMART also spun out Thrixen, a biotech startup that is developing the test into a commercially viable product.
SMART AMR completed key development of the rapid test with NTU scientists who helped design the study, provide specific reagent supplies and clinical sample collection. NUH and NCID provided consultation on clinical sample supply and testing for medical use, while MIT oversaw the project.
This work was funded by Singapore’s National Research Foundation (NRF) under the Research Campus of Excellence and Technology Enterprise (CREATE) scheme. It is also supported by Singapore’s National Medical Research Council’s Covid-19 Research Fund and the National Center for Health Innovation’s Covid-19 Gap Fund.
SMART was founded in 2007 by MIT and NRF. SMART is the first entity in CREATE. SMART is a knowledge and innovation hub that conducts cutting-edge research in areas of interest to Singapore and MIT. SMART currently includes an innovation center and five interdisciplinary research groupsa: AMR, Critical Analytics for Manufacturing Personalized Medicine, Disruptive and Sustainable Technologies for Precision Agriculture, Future Urban Mobility and Low Energy Electronic Systems.
The AMR IRG is a translational research and entrepreneurship program aimed at addressing the growing threat of antimicrobial resistance. By leveraging the talent and converging technologies of Singapore and MIT, it tackles AMR head-on by developing multiple innovative and disruptive approaches to identify, tackle and treat drug-resistant microbial infections. Through strong scientific and clinical collaborations, it delivers transformative holistic solutions to Singapore and the world.