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Multiple COVID-19 Waves and Vaccination Effectiveness in the United States

(1) Background: The coronavirus 2019 (COVID-19) pandemic has caused multiple waves of cases and deaths in the United States (US). The wild strain, the Alpha variant (B.1.1.7) and the Delta variant (B.1.617.2) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were the principal culprits...

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Autores principales: Lin, Lixin, Zhao, Yanji, Chen, Boqiang, He, Daihai
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8871705/
https://www.ncbi.nlm.nih.gov/pubmed/35206474
http://dx.doi.org/10.3390/ijerph19042282
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author Lin, Lixin
Zhao, Yanji
Chen, Boqiang
He, Daihai
author_facet Lin, Lixin
Zhao, Yanji
Chen, Boqiang
He, Daihai
author_sort Lin, Lixin
collection PubMed
description (1) Background: The coronavirus 2019 (COVID-19) pandemic has caused multiple waves of cases and deaths in the United States (US). The wild strain, the Alpha variant (B.1.1.7) and the Delta variant (B.1.617.2) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were the principal culprits behind these waves. To mitigate the pandemic, the vaccination campaign was started in January 2021. While the vaccine efficacy is less than 1, breakthrough infections were reported. This work aims to examine the effects of the vaccination across 50 US states and the District of Columbia. (2) Methods: Based on the classic Susceptible—Exposed—Infectious–Recovered (SEIR) model, we add a delay class between infectious and death, a death class and a vaccinated class. We compare two special cases of our new model to simulate the effects of the vaccination. The first case expounds the vaccinated individuals with full protection or not, compared to the second case where all vaccinated individuals have the same level of protection. (3) Results: Through fitting the two approaches to reported COVID-19 deaths in all 50 US states and the District of Columbia, we found that these two approaches are equivalent. We calculate that the death toll could be 1.67–3.33 fold in most states if the vaccine was not available. The median and mean infection fatality ratio are estimated to be approximately 0.6 and 0.7%. (4) Conclusions: The two approaches we compared were equivalent in evaluating the effectiveness of the vaccination campaign in the US. In addition, the effect of the vaccination campaign was significant, with a large number of deaths averted.
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spelling pubmed-88717052022-02-25 Multiple COVID-19 Waves and Vaccination Effectiveness in the United States Lin, Lixin Zhao, Yanji Chen, Boqiang He, Daihai Int J Environ Res Public Health Article (1) Background: The coronavirus 2019 (COVID-19) pandemic has caused multiple waves of cases and deaths in the United States (US). The wild strain, the Alpha variant (B.1.1.7) and the Delta variant (B.1.617.2) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) were the principal culprits behind these waves. To mitigate the pandemic, the vaccination campaign was started in January 2021. While the vaccine efficacy is less than 1, breakthrough infections were reported. This work aims to examine the effects of the vaccination across 50 US states and the District of Columbia. (2) Methods: Based on the classic Susceptible—Exposed—Infectious–Recovered (SEIR) model, we add a delay class between infectious and death, a death class and a vaccinated class. We compare two special cases of our new model to simulate the effects of the vaccination. The first case expounds the vaccinated individuals with full protection or not, compared to the second case where all vaccinated individuals have the same level of protection. (3) Results: Through fitting the two approaches to reported COVID-19 deaths in all 50 US states and the District of Columbia, we found that these two approaches are equivalent. We calculate that the death toll could be 1.67–3.33 fold in most states if the vaccine was not available. The median and mean infection fatality ratio are estimated to be approximately 0.6 and 0.7%. (4) Conclusions: The two approaches we compared were equivalent in evaluating the effectiveness of the vaccination campaign in the US. In addition, the effect of the vaccination campaign was significant, with a large number of deaths averted. MDPI 2022-02-17 /pmc/articles/PMC8871705/ /pubmed/35206474 http://dx.doi.org/10.3390/ijerph19042282 Text en © 2022 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Lin, Lixin
Zhao, Yanji
Chen, Boqiang
He, Daihai
Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title_full Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title_fullStr Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title_full_unstemmed Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title_short Multiple COVID-19 Waves and Vaccination Effectiveness in the United States
title_sort multiple covid-19 waves and vaccination effectiveness in the united states
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8871705/
https://www.ncbi.nlm.nih.gov/pubmed/35206474
http://dx.doi.org/10.3390/ijerph19042282
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