Newly-Developed Paper-Based Blood Test Detects COVID-19 Immunity within 10 Minutes

A newly developed paper-based blood test can determine the presence of SARS-CoV-2 neutralizing antibodies within 10 minutes.

Researchers at Singapore-MIT Alliance for Research and Technology (SMART; Singapore) have successfully developed the new rapid point-of-care test for the detection of SARS-CoV-2 neutralizing antibodies (NAbs). This simple test, only requiring a drop of blood from a fingertip, can be performed within 10 minutes without the need for a laboratory or specially trained personnel. Current NAb tests are laboratory-based, require additional equipment and trained personnel, and have a processing time of 2 to 4 days.

Despite the availability of various COVID-19 diagnostic tests, the detection of SARs-CoV-2 NAbs is still generally conducted at hospitals and specialized diagnostic laboratories. Currently, NAbs are commonly detected using virus neutralization tests (VNTs), which require handling of live virus, a facility with rigorous biosafety and containment precautions, skilled personnel and 2 to 4 days of processing time. Thus, these tests are not viable for large population testing and surveillance due to the lengthy process that may put a strain on existing laboratory capabilities. The development of a more efficient means of testing better allows for immediate point-of-care testing and mass monitoring for events or workplaces, specific localities, high traffic points, and critical points of entry such as immigration checkpoints.

According to the researchers, the newly developed rapid cellulose pull-down viral neutralization test (cpVNT) detects SARS-CoV-2 NAbs in plasma samples within 10 minutes, utilizing a vertical flow paper-based assay format and protein engineering technology. This same protein engineering technology has also been used to develop tests to detect other well-known viruses such as the Zika virus and Tuberculosis. Cellulose was adopted as a test material as it is cost-effective and easily manufactured, and to avoid reliance on nitrocellulose, which is in high demand due to its use in other rapid COVID-19 tests.

The developed test is simple to administer, non-invasive and offers quick results. To perform the test, a user mixes a drop of fingertip blood with the reaction solutions and places it on a paper strip, before inserting it into a portable reader device that will detect the NAb signals and reflect the results. This test offers up to 93% accuracy, higher than similar lab-based methods currently being used. Further development of the test is underway for its approval by regulatory authorities and manufacturing for public use. The team that has developed the tests at SMART has also spun off a biotech startup that is developing the test into a commercially ready product.

“With the gradual opening up of borders, economies and society, having the right test, and information will be crucial to not only plan for this future but also ensure that it can be done safely without hampering current efforts to curb the spread of the virus,” said Dr Megan McBee, Scientific Director at SMART AMR.

“Schools and workplaces will also benefit greatly from the test. Whether a person should be considered for receiving a booster vaccine can also be evaluated with this quick test as the results are available within minutes from a fingertip blood sample. And, if we are able to quickly determine immunity on a larger scale, the review and relaxing of COVID-related measures can be done in a more controlled, data-driven manner,” said Professor Hadley Sikes, Principal Investigator at SMART AMR, Associate Professor at MIT and a co-corresponding author of the paper.

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