COVID-19 Diagnosis and SARS-CoV-2 Strain Identification by a Rapid, Multiplexed, Point-of-Care Antibody Microarray

Antigen tests to detect SARS-CoV-2 have emerged as a promising rapid diagnostic method for COVID-19, but they are unable to differentiate between variants of concern (VOCs). Here, we report a rapid point-of-care test (POC-T), termed CoVariant-SPOT, that uses a set of antibodies that are either tolerant or intolerant to spike protein mutations to identify the likely SARS-CoV-2 strain concurrent with COVID-19 diagnosis using antibodies targeting the nucleocapsid protein. All reagents are incorporated into a portable, multiplexed, and sensitive diagnostic platform built upon a nonfouling polymer brush. To validate CoVariant-SPOT, we tested recombinant SARS-CoV-2 proteins, inactivated viruses, and nasopharyngeal swab samples from COVID-19 positive and negative individuals and showed that CoVariant-SPOT can readily distinguish between two VOCs: Delta and Omicron. We believe that CoVariant-SPOT can serve as a valuable adjunct to next-generation sequencing to rapidly identify variants using a scalable and deployable POC-T, thereby enhancing community surveillance efforts worldwide and informing treatment selection.

Automated summary

Researchers have developed a rapid point-of-care test called CoVariant-SPOT, which can identify likely variants of SARS-CoV-2 concurrent with COVID-19 diagnosis using antibodies targeting the nucleocapsid protein and spike protein mutations. The test has been shown to distinguish between two variants, Delta and Omicron, and could enhance community surveillance efforts worldwide and inform treatment selection.