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SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth
The emergence of novel SARS-CoV-2 variants of concern (VOC), in late 2020, with selective transmission advantage and partial immunity escape potential, has been driving further evolution in the pandemic. The timing of mutational evolution and its limits are thus of paramount importance in preparedne...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Elsevier Ltd.
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8507571/ https://www.ncbi.nlm.nih.gov/pubmed/34653544 http://dx.doi.org/10.1016/j.micpath.2021.105237 |
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author | Halley, John M. Vokou, Despoina Pappas, Georgios Sainis, Ioannis |
author_facet | Halley, John M. Vokou, Despoina Pappas, Georgios Sainis, Ioannis |
author_sort | Halley, John M. |
collection | PubMed |
description | The emergence of novel SARS-CoV-2 variants of concern (VOC), in late 2020, with selective transmission advantage and partial immunity escape potential, has been driving further evolution in the pandemic. The timing of mutational evolution and its limits are thus of paramount importance in preparedness planning. Here, we present a model predicting the pattern of epidemic growth including the emergence of variants through mutation. It is based on the SEIR (Susceptible, Exposed, Infected, Removed) model, but its equations are modified according to the transmission parameters of novel variants. Since more transmissible strains will drive a further increase in the number of cases, they will also lead to further novel mutations. As one cannot predict whether there is a viral mutational evolutionary limit, we model a cascade that could lead to hyper-exponential growth (HEG) involving the emergence of even more transmissible mutants that could overwhelm any systematic response. Our results are consistent with the timing, since the beginning of the pandemic, of the concurrent and independent emergence of the VOCs. The current dominance of the Delta variant and the need for additional public health measures indicates some of the risks of a possible HEG. We examine conditions that favor the expected appearance of similar variants, thus enabling better preparedness and more targeted research. |
format | Online Article Text |
id | pubmed-8507571 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | Elsevier Ltd. |
record_format | MEDLINE/PubMed |
spelling | pubmed-85075712021-10-13 SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth Halley, John M. Vokou, Despoina Pappas, Georgios Sainis, Ioannis Microb Pathog Article The emergence of novel SARS-CoV-2 variants of concern (VOC), in late 2020, with selective transmission advantage and partial immunity escape potential, has been driving further evolution in the pandemic. The timing of mutational evolution and its limits are thus of paramount importance in preparedness planning. Here, we present a model predicting the pattern of epidemic growth including the emergence of variants through mutation. It is based on the SEIR (Susceptible, Exposed, Infected, Removed) model, but its equations are modified according to the transmission parameters of novel variants. Since more transmissible strains will drive a further increase in the number of cases, they will also lead to further novel mutations. As one cannot predict whether there is a viral mutational evolutionary limit, we model a cascade that could lead to hyper-exponential growth (HEG) involving the emergence of even more transmissible mutants that could overwhelm any systematic response. Our results are consistent with the timing, since the beginning of the pandemic, of the concurrent and independent emergence of the VOCs. The current dominance of the Delta variant and the need for additional public health measures indicates some of the risks of a possible HEG. We examine conditions that favor the expected appearance of similar variants, thus enabling better preparedness and more targeted research. Elsevier Ltd. 2021-12 2021-10-12 /pmc/articles/PMC8507571/ /pubmed/34653544 http://dx.doi.org/10.1016/j.micpath.2021.105237 Text en © 2021 Elsevier Ltd. All rights reserved. Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID-19. The COVID-19 resource centre is hosted on Elsevier Connect, the company's public news and information website. Elsevier hereby grants permission to make all its COVID-19-related research that is available on the COVID-19 resource centre - including this research content - immediately available in PubMed Central and other publicly funded repositories, such as the WHO COVID database with rights for unrestricted research re-use and analyses in any form or by any means with acknowledgement of the original source. These permissions are granted for free by Elsevier for as long as the COVID-19 resource centre remains active. |
spellingShingle | Article Halley, John M. Vokou, Despoina Pappas, Georgios Sainis, Ioannis SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title | SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title_full | SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title_fullStr | SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title_full_unstemmed | SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title_short | SARS-CoV-2 mutational cascades and the risk of hyper-exponential growth |
title_sort | sars-cov-2 mutational cascades and the risk of hyper-exponential growth |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8507571/ https://www.ncbi.nlm.nih.gov/pubmed/34653544 http://dx.doi.org/10.1016/j.micpath.2021.105237 |
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