On the Evolutionary Trajectory of SARS-CoV-2: Host Immunity as a Driver of Adaptation in RNA Viruses

Abstract

Host immunity can exert a complex array of selective pressures on a pathogen, which can drive highly mutable RNA viruses towards viral escape. The plasticity of a virus depends on its rate of mutation, as well as the balance of fitness cost and benefit of mutations, including viral adaptations to the host’s immune response. Since its emergence, SARS-CoV-2 has diversified into genetically distinct variants, which are characterised often by clusters of mutations that bolster its capacity to escape human innate and adaptive immunity. Such viral escape is well documented in the context of other pandemic RNA viruses such as the human immunodeficiency virus (HIV) and influenza virus. This review describes the selection pressures the host’s antiviral immunity exerts on SARS-CoV-2 and other RNA viruses, resulting in divergence of viral strains into more adapted forms. As RNA viruses obscure themselves from host immunity, they uncover weak points in their own armoury that can inform more comprehensive, long-lasting, and potentially cross-protective vaccine coverage.

COVID-19 and flu vaccination in Romania, post pandemic lessons in healthcare workers and general population

“…RNA viruses have the power to mutate more than other viruses, their adaptability was well documented in the context of other pandemics with RNA viruses such as the human immunodeficiency virus (HIV) [ 33 – 35 ] and influenza viruses. As RNA viruses obscure themselves from host immunity, they uncover weak points in their own armory that can inform more comprehensive, long-lasting, and potentially cross-protective vaccine coverage [ 59 ].…”

Shifting the paradigm in RNA virus detection: integrating nucleic acid testing and immunoassays through single-molecule digital ELISA

“…In addition to their inherently high genetic diversity and rapid evolution, their transmission characteristics depend on their interaction with host immunity and the environment. The “survival path” of a newly emerging virus largely depends on the host’s immune response, and individuals with impaired adaptive immune responses more likely favor virus production and mutations ( 19 , 20 ). During virus transmission, virus mutations may help evade previously existing immune responses and even change mechanisms that cross over with host cell pathways and are beneficial to infection; consequently, the probability of the emergence of new viral strains increases.…”