Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.

In an epidemic, individuals can widely differ in the way they spread the infection depending on their age or on the number of days they have been infected for. In the absence of pharmaceutical interventions such as a vaccine or treatment, non-pharmaceutical interventions (e.g. physical or social dis...

Full description

Bibliographic Details
Main Authors: Quentin Richard, Samuel Alizon, Marc Choisy, Mircea T Sofonea, Ramsès Djidjou-Demasse
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2021-03-01
Series:PLoS Computational Biology
Online Access:https://doi.org/10.1371/journal.pcbi.1008776
_version_ 1819260236241829888
author Quentin Richard
Samuel Alizon
Marc Choisy
Mircea T Sofonea
Ramsès Djidjou-Demasse
author_facet Quentin Richard
Samuel Alizon
Marc Choisy
Mircea T Sofonea
Ramsès Djidjou-Demasse
author_sort Quentin Richard
collection DOAJ
description In an epidemic, individuals can widely differ in the way they spread the infection depending on their age or on the number of days they have been infected for. In the absence of pharmaceutical interventions such as a vaccine or treatment, non-pharmaceutical interventions (e.g. physical or social distancing) are essential to mitigate the pandemic. We develop an original approach to identify the optimal age-stratified control strategy to implement as a function of the time since the onset of the epidemic. This is based on a model with a double continuous structure in terms of host age and time since infection. By applying optimal control theory to this model, we identify a solution that minimizes deaths and costs associated with the implementation of the control strategy itself. We also implement this strategy for three countries with contrasted age distributions (Burkina-Faso, France, and Vietnam). Overall, the optimal strategy varies throughout the epidemic, with a more intense control early on, and depending on host age, with a stronger control for the older population, except in the scenario where the cost associated with the control is low. In the latter scenario, we find strong differences across countries because the control extends to the younger population for France and Vietnam 2 to 3 months after the onset of the epidemic, but not for Burkina Faso. Finally, we show that the optimal control strategy strongly outperforms a constant uniform control exerted over the whole population or over its younger fraction. This improved understanding of the effect of age-based control interventions opens new perspectives for the field, especially for age-based contact tracing.
first_indexed 2024-12-23T19:22:42Z
format Article
id doaj.art-79488e2c3a1f44859a5614a3391b37c2
institution Directory Open Access Journal
issn 1553-734X
1553-7358
language English
last_indexed 2024-12-23T19:22:42Z
publishDate 2021-03-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Computational Biology
spelling doaj.art-79488e2c3a1f44859a5614a3391b37c22022-12-21T17:34:06ZengPublic Library of Science (PLoS)PLoS Computational Biology1553-734X1553-73582021-03-01173e100877610.1371/journal.pcbi.1008776Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.Quentin RichardSamuel AlizonMarc ChoisyMircea T SofoneaRamsès Djidjou-DemasseIn an epidemic, individuals can widely differ in the way they spread the infection depending on their age or on the number of days they have been infected for. In the absence of pharmaceutical interventions such as a vaccine or treatment, non-pharmaceutical interventions (e.g. physical or social distancing) are essential to mitigate the pandemic. We develop an original approach to identify the optimal age-stratified control strategy to implement as a function of the time since the onset of the epidemic. This is based on a model with a double continuous structure in terms of host age and time since infection. By applying optimal control theory to this model, we identify a solution that minimizes deaths and costs associated with the implementation of the control strategy itself. We also implement this strategy for three countries with contrasted age distributions (Burkina-Faso, France, and Vietnam). Overall, the optimal strategy varies throughout the epidemic, with a more intense control early on, and depending on host age, with a stronger control for the older population, except in the scenario where the cost associated with the control is low. In the latter scenario, we find strong differences across countries because the control extends to the younger population for France and Vietnam 2 to 3 months after the onset of the epidemic, but not for Burkina Faso. Finally, we show that the optimal control strategy strongly outperforms a constant uniform control exerted over the whole population or over its younger fraction. This improved understanding of the effect of age-based control interventions opens new perspectives for the field, especially for age-based contact tracing.https://doi.org/10.1371/journal.pcbi.1008776
spellingShingle Quentin Richard
Samuel Alizon
Marc Choisy
Mircea T Sofonea
Ramsès Djidjou-Demasse
Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
PLoS Computational Biology
title Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
title_full Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
title_fullStr Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
title_full_unstemmed Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
title_short Age-structured non-pharmaceutical interventions for optimal control of COVID-19 epidemic.
title_sort age structured non pharmaceutical interventions for optimal control of covid 19 epidemic
url https://doi.org/10.1371/journal.pcbi.1008776
work_keys_str_mv AT quentinrichard agestructurednonpharmaceuticalinterventionsforoptimalcontrolofcovid19epidemic
AT samuelalizon agestructurednonpharmaceuticalinterventionsforoptimalcontrolofcovid19epidemic
AT marcchoisy agestructurednonpharmaceuticalinterventionsforoptimalcontrolofcovid19epidemic
AT mirceatsofonea agestructurednonpharmaceuticalinterventionsforoptimalcontrolofcovid19epidemic
AT ramsesdjidjoudemasse agestructurednonpharmaceuticalinterventionsforoptimalcontrolofcovid19epidemic