Test developed at Duke can quickly tell who has antibodies to fight which variant of coronavirus :: WRAL.com

By Matt Talhelm, WRAL reporter, & Matthew Burns, WRAL.com senior producer / political editor

Durham, North Carolina – Biomedical engineers at Duke University have designed a test to quickly and easily assess how well a person’s antibodies fight infection with several variants of the coronavirus.

The test, dubbed the COVID-19 Variant Spike-ACE2-Competitive Antibody Neutralization test, or CoVariant-SCAN, could potentially tell physicians how protected a patient is against the variants circulating in a community as well as the news. It could also indicate which monoclonal antibody treatments would best help a patient.

“We currently have no rapid way to assess variants, neither their presence in an individual nor the ability of the antibodies we have to tell the difference,” said Dr Cameron Wolfe, associate professor of medicine at Duke University. School of Medicine, in a statement. “It is one of the lingering fears that as we succeed in vaccinating more and more people, a variant may emerge that more drastically escapes the vaccine-induced neutralization of antibodies. What if that fear comes true – if omicron turns out to be the worst case scenario – how would we know fast enough? “

The technology in the test relies on a polymer brush coating that acts as a non-stick surface to stop anything but the desired biomarkers to attach to a test slide when wet. The effectiveness of the non-stick shield makes the assay sensitive even at low levels of its targets and allows researchers to print different molecular traps on various areas of the slide to capture multiple biomarkers at a time, testing protection against multiple variants with a single test.

Researchers printed fluorescent human ACE2 proteins – the cellular targets of the famous coronavirus peak protein – on a slide. They also imprinted tip proteins specific to each variant in different places on the slide. When the test is run, the ACE2 proteins break off and are captured by the spike proteins on the slide, causing it to glow.

But in the presence of antibodies, the spike proteins are not able to grab ACE2 proteins, which makes the slide less bright and indicates the effectiveness of the antibodies. By printing different variants of the spike protein on different parts of the slide, researchers can see how effective the antibodies are at preventing each variant from attaching to their human cellular target.

To determine a person’s resistance to viral variants, scientists currently have to isolate a live virus and grow some cells, which can take 24 hours or more and requires various safety precautions and specially trained technicians. Duke researchers said the CoVariant-SCAN test requires no live virus, can be used in most settings, and takes less than one hour – maybe as little as 15 minutes – To produce precise results.

“We would like to have real-time visibility of emerging variants and understand who still has functional immunity,” Wolfe said. “To be able to pre-to screen for an individual’s antibodies and predict whether they were sufficiently protected against a particular variant that they may be about to encounter during traveling or emerging in their region. we have no way of doing that at the moment. “

Researchers are now working to streamline the technique into a chip that could be mass-produced and report results with just a few drops of blood, plasma, or other liquid samples containing antibodies.

The research was conducted by a team led by Ashutosh Tchilkoti, Alan L. Kaganov Distinguished Professor and Chairman of the Department of Biomedical Engineering at Duke, and has been funded by the National Institutes of Health, the National Science Foundation and the Defense Advanced Research Projects Agency of the Department of Defense. It was published online Friday in the journal Science Advances.