SARS-CoV-2 virulence evolution: Avirulence theory, immunity and trade-offs

The COVID-19 pandemic has led to a resurgence of the debate on whether host-parasite interactions should evolve towards avirulence. In this review, we first show that SARS-CoV-2 virulence is evolving, before explaining why some expect the mortality caused by the epidemic to converge towards that of human seasonal alphacoronaviruses. Leaning on existing theory, we then include viral evolution into the picture and discuss hypotheses explaining why the virulence has increased since the beginning of the pandemic. Finally, we mention some potential scenarios for the future.

Automated summary

This review discusses the resurgence of the debate on whether host-parasite interactions should evolve towards avirulence due to the COVID-19 pandemic. It shows that SARS-CoV-2 virulence is evolving and explains why some expect mortality caused by the epidemic to converge with that of human seasonal alphacoronaviruses. The review includes viral evolution theories, hypotheses regarding increased virulence, and potential scenarios for the future.