ADESSO detects SARS-CoV-2 and its variants: extensive clinical validation of an optimised CRISPR-Cas13-based COVID-19 test

SARS-CoV-2 is the causative agent for a pandemic that has had immense consequences for the health and economic sectors worldwide. While PCR testing and later antigen tests have proven critical for helping to stem the spread of the virus, these methods suffer from general applicability and sensitivity, respectively. Moreover, the emergence of variant strains creates the need for flexibility to correctly and efficiently diagnose the presence of substrains in the population. To address these needs we have developed the diagnostic test ADESSO (Accurate Detection of Evolving SARS-CoV-2 through SHERLOCK Optimization) which employs the Cas13 system to diagnose patients in as little as 1 hour without sophisticated equipment. Using an extensive panel of clinical samples, we demonstrate that ADESSO correctly identifies COVID-19 positive samples at a sensitivity and specificity comparable to RT-qPCR on extracted RNA and higher than antigen tests for unextracted samples. Taken together, ADESSO is a fast, sensitive and cheap method that can be applied in a point of care (POC) setting to diagnose COVID-19 and can be quickly adjusted to detect new variants.