Research develops rapid test to identify e ectiveness of antibodies against Covid-19 variants

December 7


THE research has been published in the ‘Science Advances Journal’. This test could potentially tell doctors how protected a patient is from new variants and those currently circulating in a community or, conversely, which monoclonal antibodies to treat a COVID-19 patient.


“We currently really have no rapid way of assessing variants, neither their presence in an individual nor the ability of antibodies we possess to make a difference,” said Cameron Wolfe, associate professor of medicine at the Duke University School of Medicine.


“It’s one of the lingering fears that, as we successfully vaccinate more and more people, a variant may emerge that more radically evades vaccine-induced antibody neutralization. And if that fear came true - if Omicron turned out to be a worst-case scenario - how would we know quickly enough?” Wolfe added.


“While developing a point-ofcare test for COVID-19 antibodies and biomarkers, we realized there could be some benefit to being able to detect the ability of antibodies to neutralize specific variants, so we built a test around that idea,” said Ashutosh Chilkoti, the Alan L. Kaganov Distinguished Professor and Chair of Biomedical Engineering at Duke.


“It only took us a week or two to incorporate the Delta variant in our test, and it could easily be expanded to also include the Omicron variant. All we need is the spike protein of this variant, which many groups across the world — including our group at Duke — are feverishly working to produce,” Chilkoti added.


The researchers have dubbed their test the COVID-19 Variant Spike-ACE2-Competitive Antibody Neutralization assay, or CoVariant-SCAN for short. The test’s technology hinged on a polymer brush coating that acted as a sort of non-stick coating to stop anything but the desired biomarkers from attaching to the test slide when wet. The high effectiveness of this non-stick shield made the test incredibly sensitive to even low levels of its targets. The approach allowed the researchers to print different molecular traps on different areas of the slide to catch multiple biomarkers at once.


In this application, researchers printed fluorescent human ACE2 proteins — the cellular targets of the virus’s infamous spike protein — on a slide. They also printed spike proteins specific to each variant of COVID-19 at different specific locations. When the test was run, the ACE2 proteins detached from the slide and were caught by the spike proteins still attached to the slide, causing the slide to glow. SOURCE: AN