tetano
Editor, Senior Moderator
Emerg Microbes Infect
. 2022 Apr 5;1-52.
doi: 10.1080/22221751.2022.2063073. Online ahead of print.
Assessing the transition of COVID-19 burden towards the young population while vaccines are rolled out in China
Jun Cai[SUP] 1 [/SUP], Juan Yang[SUP] 1 2 3 [/SUP], Xiaowei Deng[SUP] 1 [/SUP], Cheng Peng[SUP] 1 [/SUP], Xinhua Chen[SUP] 1 [/SUP], Qianhui Wu[SUP] 1 [/SUP], Hengcong Liu[SUP] 1 [/SUP], Juanjuan Zhang[SUP] 1 2 3 [/SUP], Wen Zheng[SUP] 1 [/SUP], Junyi Zou[SUP] 1 [/SUP], Zeyao Zhao[SUP] 1 [/SUP], Marco Ajelli[SUP] 4 [/SUP], Hongjie Yu[SUP] 1 2 3 [/SUP]
Affiliations
Abstract
SARS-CoV-2 infection causes most cases of severe illness and fatality in older age groups. Over 92% of the Chinese population aged ≥12 years has been fully vaccinated against COVID-19 (albeit with vaccines developed against historical lineages). At the end of October 2021, the vaccination program has been extended to children aged 3-11 years. Here, we aim to assess whether, in this vaccination landscape, the importation of Delta variant infections could shift COVID-19 burden from adults to children. We developed an age-structured susceptible-infectious-removed model of SARS-CoV-2 transmission to simulate epidemics triggered by the importation of Delta variant infections and project the age-specific incidence of SARS-CoV-2 infections, cases, hospitalisations, intensive care unit (ICU) admissions, and deaths. In the context of the vaccination program targeting individuals aged ≥12 years, and in the absence of non-pharmaceutical interventions, the importation of Delta variant infections could have led to widespread transmission and substantial disease burden in mainland China, even with vaccination coverage as high as 89% across the eligible age groups. Extending the vaccination roll-out to include children aged 3-11 years (as it was the case since the end of October 2021) is estimated to dramatically decrease the burden of symptomatic infections and hospitalisations within this age group (39% and 68%, respectively, when considering a vaccination coverage of 87%), but would have a low impact on protecting infants. Our findings highlight the importance of including children among the target population and the need to strengthen vaccination efforts by increasing vaccine effectiveness.Trial registration: ClinicalTrials.gov identifier: NCT04847102..
Keywords: China; Delta variant; children; novel coronavirus disease 2019; transition of disease burden; vaccination.
. 2022 Apr 5;1-52.
doi: 10.1080/22221751.2022.2063073. Online ahead of print.
Assessing the transition of COVID-19 burden towards the young population while vaccines are rolled out in China
Jun Cai[SUP] 1 [/SUP], Juan Yang[SUP] 1 2 3 [/SUP], Xiaowei Deng[SUP] 1 [/SUP], Cheng Peng[SUP] 1 [/SUP], Xinhua Chen[SUP] 1 [/SUP], Qianhui Wu[SUP] 1 [/SUP], Hengcong Liu[SUP] 1 [/SUP], Juanjuan Zhang[SUP] 1 2 3 [/SUP], Wen Zheng[SUP] 1 [/SUP], Junyi Zou[SUP] 1 [/SUP], Zeyao Zhao[SUP] 1 [/SUP], Marco Ajelli[SUP] 4 [/SUP], Hongjie Yu[SUP] 1 2 3 [/SUP]
Affiliations
- PMID: 35380100
- DOI: 10.1080/22221751.2022.2063073
Abstract
SARS-CoV-2 infection causes most cases of severe illness and fatality in older age groups. Over 92% of the Chinese population aged ≥12 years has been fully vaccinated against COVID-19 (albeit with vaccines developed against historical lineages). At the end of October 2021, the vaccination program has been extended to children aged 3-11 years. Here, we aim to assess whether, in this vaccination landscape, the importation of Delta variant infections could shift COVID-19 burden from adults to children. We developed an age-structured susceptible-infectious-removed model of SARS-CoV-2 transmission to simulate epidemics triggered by the importation of Delta variant infections and project the age-specific incidence of SARS-CoV-2 infections, cases, hospitalisations, intensive care unit (ICU) admissions, and deaths. In the context of the vaccination program targeting individuals aged ≥12 years, and in the absence of non-pharmaceutical interventions, the importation of Delta variant infections could have led to widespread transmission and substantial disease burden in mainland China, even with vaccination coverage as high as 89% across the eligible age groups. Extending the vaccination roll-out to include children aged 3-11 years (as it was the case since the end of October 2021) is estimated to dramatically decrease the burden of symptomatic infections and hospitalisations within this age group (39% and 68%, respectively, when considering a vaccination coverage of 87%), but would have a low impact on protecting infants. Our findings highlight the importance of including children among the target population and the need to strengthen vaccination efforts by increasing vaccine effectiveness.Trial registration: ClinicalTrials.gov identifier: NCT04847102..
Keywords: China; Delta variant; children; novel coronavirus disease 2019; transition of disease burden; vaccination.