SARS-CoV-2 mutation identification: a look at the latest solutions

Recent reports of potentially more dangerous SARS-CoV-2 mutants such as the Delta variant highlight the need for surveillance to quickly identify changes in the viral genome and contain their spread. The World Health Organization (WHO) has designated the four variants Alpha, Beta, Gamma and Delta as variants of concern (VOCs).¹ These variants are of particular concern because they may spread faster and/or may cause more severe disease. Additionally, variants may impact the performance of current diagnostic approaches or the effectiveness of vaccines.¹ Currently, the WHO is urging countries to expand their variant detection efforts to track sub-lineages of the Delta variant, which is currently the most worrisome of the VOCs.

Diagnostic testing versus variant detection

Diagnostic testing is used to detect SARS-CoV-2 infection and to inform an individual’s medical care. Additionally, diagnostic results are used to reduce the transmission of SARS-CoV-2 by identifying infected persons who need to isolate from others. Two types of viral test can be used for diagnosis: nucleic acid amplification tests, which include RT-PCR assays, and antigen tests.² These first-tier detection assays provide limited information about SARS-CoV-2 variants.