Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022
Clusters of COVID-19 in high-risk settings, such as schools, have been deemed a critical driving force of the major epidemic waves at the societal level. In Japan, the vaccination coverage among students remained low up to early 2022, especially for 5–11-year-olds. The vaccination of the student pop...
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AIMS Press
2024-09-01
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| Series: | Mathematical Biosciences and Engineering |
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| Online Access: | https://www.aimspress.com/article/doi/10.3934/mbe.2024312 |
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| author | Yuta Okada Hiroshi Nishiura |
| author_facet | Yuta Okada Hiroshi Nishiura |
| author_sort | Yuta Okada |
| collection | DOAJ |
| description | Clusters of COVID-19 in high-risk settings, such as schools, have been deemed a critical driving force of the major epidemic waves at the societal level. In Japan, the vaccination coverage among students remained low up to early 2022, especially for 5–11-year-olds. The vaccination of the student population only started in February 2022. Given this background and considering that vaccine effectiveness against school transmission has not been intensively studied, this paper proposes a mathematical model that links the occurrence of clustering to the case count among populations aged 0–19, 20–59, and 60+ years of age. We first estimated the protected (immune) fraction of each age group either by infection or vaccination and then linked the case count in each age group to the number of clusters via a time series regression model that accounts for the time-varying hazard of clustering per infector. From January 3 to May 30, 2022, there were 4,722 reported clusters in school settings. Our model suggests that the immunity offered by vaccination averted 226 (95% credible interval: 219–232) school clusters. Counterfactual scenarios assuming elevated vaccination coverage with faster roll-out reveal that additional school clusters could have been averted. Our study indicates that even relatively low vaccination coverage among students could substantially lower the risk of clustering through vaccine-induced immunity. Our results also suggest that antigenically updated vaccines that are more effective against the variant responsible for the ongoing epidemic may greatly help decrease not only the incidence but also the unnecessary loss of learning opportunities among school-age students. |
| format | Article |
| id | doaj-art-9360e0bf9b05409fa1ed44543afb05cc |
| institution | Kabale University |
| issn | 1551-0018 |
| language | English |
| publishDate | 2024-09-01 |
| publisher | AIMS Press |
| record_format | Article |
| series | Mathematical Biosciences and Engineering |
| spelling | doaj-art-9360e0bf9b05409fa1ed44543afb05cc2025-01-23T07:47:53ZengAIMS PressMathematical Biosciences and Engineering1551-00182024-09-012197087710110.3934/mbe.2024312Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022Yuta Okada0Hiroshi Nishiura1Kyoto University School of Public Health, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8601, JapanKyoto University School of Public Health, Yoshida-Konoe, Sakyo-ku, Kyoto 606-8601, JapanClusters of COVID-19 in high-risk settings, such as schools, have been deemed a critical driving force of the major epidemic waves at the societal level. In Japan, the vaccination coverage among students remained low up to early 2022, especially for 5–11-year-olds. The vaccination of the student population only started in February 2022. Given this background and considering that vaccine effectiveness against school transmission has not been intensively studied, this paper proposes a mathematical model that links the occurrence of clustering to the case count among populations aged 0–19, 20–59, and 60+ years of age. We first estimated the protected (immune) fraction of each age group either by infection or vaccination and then linked the case count in each age group to the number of clusters via a time series regression model that accounts for the time-varying hazard of clustering per infector. From January 3 to May 30, 2022, there were 4,722 reported clusters in school settings. Our model suggests that the immunity offered by vaccination averted 226 (95% credible interval: 219–232) school clusters. Counterfactual scenarios assuming elevated vaccination coverage with faster roll-out reveal that additional school clusters could have been averted. Our study indicates that even relatively low vaccination coverage among students could substantially lower the risk of clustering through vaccine-induced immunity. Our results also suggest that antigenically updated vaccines that are more effective against the variant responsible for the ongoing epidemic may greatly help decrease not only the incidence but also the unnecessary loss of learning opportunities among school-age students.https://www.aimspress.com/article/doi/10.3934/mbe.2024312vaccine effectivenesscoronavirus disease 2019 (covid-19)population-level immunitytransmission clusterclassroom closuretime series regression model |
| spellingShingle | Yuta Okada Hiroshi Nishiura Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 Mathematical Biosciences and Engineering vaccine effectiveness coronavirus disease 2019 (covid-19) population-level immunity transmission cluster classroom closure time series regression model |
| title | Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 |
| title_full | Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 |
| title_fullStr | Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 |
| title_full_unstemmed | Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 |
| title_short | Vaccine-induced reduction of COVID-19 clusters in school settings in Japan during the epidemic wave caused by B.1.1.529 (Omicron) BA.2, 2022 |
| title_sort | vaccine induced reduction of covid 19 clusters in school settings in japan during the epidemic wave caused by b 1 1 529 omicron ba 2 2022 |
| topic | vaccine effectiveness coronavirus disease 2019 (covid-19) population-level immunity transmission cluster classroom closure time series regression model |
| url | https://www.aimspress.com/article/doi/10.3934/mbe.2024312 |
| work_keys_str_mv | AT yutaokada vaccineinducedreductionofcovid19clustersinschoolsettingsinjapanduringtheepidemicwavecausedbyb11529omicronba22022 AT hiroshinishiura vaccineinducedreductionofcovid19clustersinschoolsettingsinjapanduringtheepidemicwavecausedbyb11529omicronba22022 |