Within-Host and Between-Host Evolution in SARS-CoV-2-New Variant's Source

Viruses. 2021 Apr 25;13(5):751. doi: 10.3390/v13050751.

Abstract

Some of the newly emerging corona viral variants show high numbers of mutations. This is unexpected for a virus with a low mutation rate due to an inherent proof-reading system. Could such a variant arise under very special conditions occurring in a host where the virus replicates and mutates in a rather unlimited fashion, such as in immune compromised patients? The virus was shown to replicate in an immunosuppressed cancer patient for more than 105 days and might be a source of new variants. These patients are asymptomatic and the virus may therefore escape detection and attention and be high-risk. Similarly, HIV-infected individuals may be immunocompromised and support coronavirus replication with increased mutation rates. The patients may promote "within-host evolution". Some of the viruses present in such a highly mutagenic swarm or quasispecies within one patient may become founders and cause a pandemic by further "between-host evolution". B.1.1.7 with 23 mutations may be such a case. Immunosuppressed patients can be identified and treated by the synthetic antibody cocktails as passive immunization and kept under control. Immunosuppressed patients can be easily identified and supervised by healthcare workers-once they become aware of the risk-to avoid new variants with pandemic potential.

Keywords: corona; emerging variants; immunosuppression; origin; pandemic; prevention; risk.

MeSH terms

  • Brazil
  • COVID-19 / virology*
  • Evolution, Molecular
  • Genome, Viral
  • Health Personnel
  • Host-Pathogen Interactions
  • Humans
  • Immunization, Passive
  • Immunosuppression Therapy
  • Influenza, Human
  • Mutagenesis
  • Mutation Rate
  • Mutation*
  • Orthomyxoviridae / genetics
  • Pandemics
  • Quasispecies
  • SARS-CoV-2 / genetics*