CRISPR detectives against SARS-CoV-2: a major setback against COVID-19 blowout

The emergence of SARS-CoV-2 has brought the world to a standstill, and till date, effective treatments and diagnostics against this idiosyncratic pathogen are lacking. As compared to the standard WHO/CDC qPCR detection method, which consumes several hours for detection, CRISPR-based SHERLOCK, DETECTR, and FELUDA have emerged as rapid diagnostic tools for the detection of the RNA genome of SARS-CoV-2 within an hour with 100% accuracy, specificity, and sensitivity. These attributes of CRISPR-based detection technologies have taken themselves one step ahead of available detection systems and are emerging as an inevitable tool for quick detection of the virus. Further, the discovery of Cas13s nucleases and their orthologs has opened a new corridor for exploitation of Cas13s as an antiviral therapy against SARS-CoV-2 and other viral diseases. One such approach is Prophylactic Antiviral CRISPR in huMAN cells (PACMAN), which needs a long haul to bring into therapy. The approval of SHERLOCK as the first CRISPR-based SARS-CoV-2 test kit by the FDA, for emergency diagnosis of COVID-19 patients, has given positive hope to scientists that sooner human trials of CRISPR-based therapy will be ratified. In this review, we have extensively reviewed the present CRISPR-based approaches, challenges, and future prospects in the light of diagnostics and therapeutics against SARS-CoV-2. KEY POINTS: • The discovery of Cas12 and Cas13 siblings allowed scientists to detect the viral genes. • Cas13d's identification aided scientists in precisely cleaving the SARS-CoV-2 ssRNA. • CRISPR-Cas system acts as "molecular detector and antiviral proctor."