The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants

Abstract Several vaccines with different efficacies and effectivenesses are currently being distributed across the world to control the COVID-19 pandemic. Having enough doses from the most efficient vaccines in a short time is not possible for all countries. Hence, policymakers may propose using var...

Descripción completa

Guardado en:

Detalles Bibliográficos
Autores principales:	Iraj Yadegari, Mehdi Omidi, Stacey R. Smith
Formato:	article
Lenguaje:	EN
Publicado:	Nature Portfolio 2021
Materias:	Medicine R Science Q
Acceso en línea:	https://doaj.org/article/bb00c4e0d69d42028cf528b0edddfc0d
Etiquetas:	Agregar Etiqueta Sin Etiquetas, Sea el primero en etiquetar este registro!

id	oai:doaj.org-article:bb00c4e0d69d42028cf528b0edddfc0d
record_format	dspace
spelling	oai:doaj.org-article:bb00c4e0d69d42028cf528b0edddfc0d2021-11-28T12:19:24ZThe herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants10.1038/s41598-021-00083-22045-2322https://doaj.org/article/bb00c4e0d69d42028cf528b0edddfc0d2021-11-01T00:00:00Zhttps://doi.org/10.1038/s41598-021-00083-2https://doaj.org/toc/2045-2322Abstract Several vaccines with different efficacies and effectivenesses are currently being distributed across the world to control the COVID-19 pandemic. Having enough doses from the most efficient vaccines in a short time is not possible for all countries. Hence, policymakers may propose using various combinations of available vaccines to control the pandemic with vaccine-induced herd immunity by vaccinating a fraction of the population. The classic vaccine-induced herd-immunity threshold suggests that we can stop spreading the disease by vaccinating a fraction of the population. However, that classic threshold is defined only for a single vaccine and may be invalid and biased when we have multi-vaccine strategies for a disease or multiple variants, potentially leading policymakers to suboptimal vaccine-allocation policies. Here, we determine which combination of multiple vaccines may lead to herd immunity. We show that simplifying the problem and considering the vaccination of the population as a single-vaccine strategy whose effectiveness is the sample mean of all effectivenesses would not be ideal, because many multi-vaccine strategies with a smaller herd-immunity threshold can be proposed. We show that the herd-immunity threshold may vary due to changes in vaccine-uptake proportions. Moreover, we propose methods to determine the optimal combination of multiple vaccines in order to achieve herd immunity and apply our results to the issue of multiple variants. In addition, we determine a condition for reaching herd immunity in the presence of new emerging variants of concern. We show by example that new variants could influence our estimation of the vaccination reproduction number. It follows that the herd-immunity threshold must be updated not only when multi-vaccine strategies are used but also when multiple variants coexist in the population.Iraj YadegariMehdi OmidiStacey R. SmithNature PortfolioarticleMedicineRScienceQENScientific Reports, Vol 11, Iss 1, Pp 1-11 (2021)
institution	DOAJ
collection	DOAJ
language	EN
topic	Medicine R Science Q
spellingShingle	Medicine R Science Q Iraj Yadegari Mehdi Omidi Stacey R. Smith The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
description	Abstract Several vaccines with different efficacies and effectivenesses are currently being distributed across the world to control the COVID-19 pandemic. Having enough doses from the most efficient vaccines in a short time is not possible for all countries. Hence, policymakers may propose using various combinations of available vaccines to control the pandemic with vaccine-induced herd immunity by vaccinating a fraction of the population. The classic vaccine-induced herd-immunity threshold suggests that we can stop spreading the disease by vaccinating a fraction of the population. However, that classic threshold is defined only for a single vaccine and may be invalid and biased when we have multi-vaccine strategies for a disease or multiple variants, potentially leading policymakers to suboptimal vaccine-allocation policies. Here, we determine which combination of multiple vaccines may lead to herd immunity. We show that simplifying the problem and considering the vaccination of the population as a single-vaccine strategy whose effectiveness is the sample mean of all effectivenesses would not be ideal, because many multi-vaccine strategies with a smaller herd-immunity threshold can be proposed. We show that the herd-immunity threshold may vary due to changes in vaccine-uptake proportions. Moreover, we propose methods to determine the optimal combination of multiple vaccines in order to achieve herd immunity and apply our results to the issue of multiple variants. In addition, we determine a condition for reaching herd immunity in the presence of new emerging variants of concern. We show by example that new variants could influence our estimation of the vaccination reproduction number. It follows that the herd-immunity threshold must be updated not only when multi-vaccine strategies are used but also when multiple variants coexist in the population.
format	article
author	Iraj Yadegari Mehdi Omidi Stacey R. Smith
author_facet	Iraj Yadegari Mehdi Omidi Stacey R. Smith
author_sort	Iraj Yadegari
title	The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
title_short	The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
title_full	The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
title_fullStr	The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
title_full_unstemmed	The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
title_sort	herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants
publisher	Nature Portfolio
publishDate	2021
url	https://doaj.org/article/bb00c4e0d69d42028cf528b0edddfc0d
work_keys_str_mv	AT irajyadegari theherdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants AT mehdiomidi theherdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants AT staceyrsmith theherdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants AT irajyadegari herdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants AT mehdiomidi herdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants AT staceyrsmith herdimmunitythresholdmustbeupdatedformultivaccinestrategiesandmultiplevariants
_version_	1718408099773022208

The herd-immunity threshold must be updated for multi-vaccine strategies and multiple variants

Ejemplares similares