CAIMS Code of Conduct
“All participants are expected to comply with the CAIMS-SCMAI Code of Conduct”
Within-host evolution of SARS-CoV-2: how often are de novo mutations transmitted?
As of March 10th, 2023, the total number of reported SARS-CoV-2 infections reached over 676 million world wide. Despite a relatively low mutation rate, the large number of infections has allowed for substantial genetic change in SARS-CoV-2, leading to a multitude of “variants of concern”. Utilizing recently determined mutations rates (per site replication), as well as within-host parameter estimates for hospitalized SARS-CoV-2 infections, we applied a stochastic transmission bottleneck model to describe the survival probability of rare de novo SARS-CoV-2 mutations. In the first part of this talk I will briefly discuss the significance and relevance of our within-host parameters published in ref.[1]. I will then discuss our un-published work on SARS-CoV-2 within-host evolution where we compute the survival probability of neutral mutations (no phenotypic effect), and various mutations affecting viral life history. We examine transmission bottlenecks of varying sizes, estimating which mutations are most likely to occur de novo and be transmitted during a single infection. This work offers both a null model for SARS-CoV-2 substitution rates and predicts which aspects of viral life history are most likely to successfully evolve, despite low mutation rates and repeated transmission bottlenecks. [1] C.S.Korosec et al., Journal of theoretical biology, 564, 2023.