Viral evolution articles from across Nature Portfolio

XBB is the first recombinant, globally dominant variant of SARS-CoV-2. Here, the authors examine the variant’s origins and virological properties, showing it is the first example of SARS-CoV-2 improving its fitness through recombination.

RNA viruses are defined by linear RNA genomes encoding an RNA-dependent RNA polymerase, while viroid-like elements consist of small, single-stranded, circular RNA genomes that, in some cases, encode self-cleaving catalytic RNAs. Here, the authors identify over 20,000 candidate viroid-like elements, and show that infectious agents of fungi display hybrid features of viroid-like RNAs and RNA viruses.

Antibodies against SARS-CoV-2 can be used to treat infections but there is a risk of driving viral resistance to antibodies. Here the authors characterise SARS-CoV-2 escape mutants from an immunocompromised patient treated with anti-SARS-CoV-2 antibodies using mouse protection studies and structural prediction.

In this Review, Markov, Katzourakis and colleagues explore the evolution of SARS-CoV-2 at different scales, the phases of the COVID-19 pandemic, factors that drive the evolution of the virus, theories for the emergence of epidemiologically important variants and potential future evolutionary scenarios and their likely health repercussions.

There is limited data on within-host SARS-CoV-2 genetic diversity and how it is affected by vaccination. The authors analysed intra-host sequence diversity and found that VOCs may have more sequence variations than non-VOCs and that breakthrough infections in vaccinated individuals do not seem to increase non-silent mutations.

The murine norovirus NTPase NS3 induces mitochondrial disruption, resulting in cell death, which is required for viral egress.