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Visualization of SARS-CoV-2 using Immuno RNA-Fluorescence In Situ Hybridization
Published on: December 23, 2020
Within-host evolutionary dynamics and tissue compartmentalization during acute SARS-CoV-2 infection
Mireille Farjo1, Katia Koelle2, Michael A Martin2,3
1Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
Daily sampling reveals SARS-CoV-2 evolution within hosts. Viral genetic changes were mostly random, but some variants transmitted, and distinct viral populations existed in saliva and nasal samples.
Area of Science:
- Virology
- Evolutionary Biology
- Genomics
Background:
- Global SARS-CoV-2 evolution is influenced by within-host dynamics.
- Host immune history impacts viral evolution.
- Understanding acute infection evolutionary trajectories is crucial.
Purpose of the Study:
- To characterize the within-host evolution of SARS-CoV-2 during acute infection.
- To compare viral evolutionary dynamics in vaccinated and unvaccinated individuals.
- To investigate viral genetic compartmentalization between sample sites.
Main Methods:
- Daily sequencing of saliva and nasal samples from 31 individuals.
- Longitudinal sampling strategy for high-confidence variant detection.
- Analysis of mutational accumulation and variant dynamics.
Main Results:
- Longitudinal sampling revealed evolutionary dynamics missed by infrequent sampling.
- Within-host viral dynamics were largely stochastic in both vaccinated and unvaccinated individuals.
- Significant genetic compartmentalization of SARS-CoV-2 variants was observed between saliva and nasal samples.
Conclusions:
- Daily sampling provides a high-resolution profile of within-host SARS-CoV-2 evolution.
- Stochastic processes, selection, genetic drift, and spatial compartmentalization shape viral evolution.
- Rare transmission-ready variants emerged from within-host evolution.
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