Interferon Resistance of Emerging SARS-CoV-2 Variants

The emergence of SARS-CoV-2 variants with enhanced transmissibility, pathogenesis and resistance to vaccines presents urgent challenges for curbing the COVID-19 pandemic. While Spike mutations that enhance virus infectivity may drive the emergence of these novel variants, studies documenting a critical a role for interferon responses in the early control of SARS-CoV-2 infection, combined with the presence of viral genes that limit these responses, suggest that interferons may also influence SARS-CoV-2 evolution. Here, we compared the potency of 17 different human interferons against 5 viral lineages sampled during the course of the global outbreak that included ancestral and emerging variants. Our data revealed increased interferon resistance in emerging SARS-CoV-2 variants, indicating that evasion of innate immunity is a significant driving force for SARS-CoV-2 evolution. These findings have implications for the increased lethality of emerging variants and highlight the interferon subtypes that may be most successful in the treatment of early infections.