Publications
Chamberlain, Heather R.; Lazar, Attila N.; Tatem, Andrew J.
High-resolution estimates of social distancing feasibility, mapped for urban areas in sub-Saharan Africa Journal Article
In: Scientific Data, vol. 9, no. 711, 2022.
Abstract | Links | BibTeX | Tags: Africa, covid-19, NPIs
@article{nokey,
title = {High-resolution estimates of social distancing feasibility, mapped for urban areas in sub-Saharan Africa},
author = {Heather R. Chamberlain and Attila N. Lazar and Andrew J. Tatem },
doi = {10.1038/s41597-022-01799-0},
year = {2022},
date = {2022-11-18},
journal = {Scientific Data},
volume = {9},
number = {711},
abstract = {Social distancing has been widely-implemented as a public health measure during the COVID-19 pandemic. Despite widespread application of social distancing guidance, the feasibility of people adhering to such guidance varies in different settings, influenced by population density, the built environment and a range of socio-economic factors. Social distancing constraints however have only been identified and mapped for limited areas. Here, we present an ease of social distancing index, integrating metrics on urban form and population density derived from new multi-country building footprint datasets and gridded population estimates. The index dataset provides estimates of social distancing feasibility, mapped at high-resolution for urban areas across 50 countries in sub-Saharan Africa.},
keywords = {Africa, covid-19, NPIs},
pubstate = {published},
tppubtype = {article}
}
Lai, Shengjie; Bogoch, Isaac I; Ruktanonchai, Nick W; Watts, Alexander; Lu, Xin; Yang, Weizhong; Yu, Hongjie; Khan, Kamran; Tatem, Andrew J
Assessing spread risk of COVID-19 within and beyond China in early 2020 Journal Article
In: Data Science and Management, 2022.
Abstract | Links | BibTeX | Tags: China, covid-19, Mobility
@article{,
title = {Assessing spread risk of COVID-19 within and beyond China in early 2020},
author = {Lai, Shengjie and Bogoch, Isaac I and Ruktanonchai, Nick W and Watts, Alexander and Lu, Xin and Yang, Weizhong and Yu, Hongjie and Khan, Kamran and Tatem, Andrew J},
doi = {10.1016/j.dsm.2022.08.004},
year = {2022},
date = {2022-08-26},
urldate = {2022-08-26},
journal = {Data Science and Management},
abstract = {A novel coronavirus emerged in Wuhan in late 2019 and has caused the COVID-19 pandemic announced by the World Health Organization on March 12, 2020. This study was originally conducted in January 2020 to estimate the potential risk and geographic range of COVID-19 spread within and beyond China at the early stage of the pandemic. A series of connectivity and risk analyses based on domestic and international travel networks were conducted using historical aggregated mobile phone data and air passenger itinerary data. We found that the cordon sanitaire of Wuhan was likely to have occurred during the latter stages of peak population numbers leaving the city, with travellers departing into neighbouring cities and other megacities in China. We estimated that 59,912 air passengers, of which 834 (95% uncertainty interval: 478–1349) had COVID-19 infection, travelled from Wuhan to 382 cities outside of mainland China during the two weeks prior to the city’s lockdown. Most of these destinations were located in Asia, but major hubs in Europe, the US and Australia were also prominent, with a strong correlation seen between the predicted risks of importation and the number of imported cases found. Given the limited understanding of emerging infectious diseases in the very early stages of outbreaks, our approaches and findings in assessing travel patterns and risk of transmission can help guide public health preparedness and intervention design for new COVID-19 waves caused by variants of concern and future pandemics to effectively limit transmission beyond its initial extent.},
keywords = {China, covid-19, Mobility},
pubstate = {published},
tppubtype = {article}
}
Ge, Yong; Zhang, Wen-Bin; Wu, Xilin; Ruktanonchai, Corrine W; Liu, Haiyan; Wang, Jianghao; Song, Yongze; Liu, Mengxiao; Yan, Wei; Yang, Juan; Cleary, Eimear; Qader, Sarchil H.; Atuhaire, Fatumah; Ruktanonchai, Nick W.; Tatem, Andrew J.; Shengjie, Lai
Untangling the changing impact of non-pharmaceutical interventions and vaccination on European COVID-19 trajectories Journal Article
In: Nature Communications, vol. 13, iss. 3106, 2022.
Abstract | Links | BibTeX | Tags: covid-19, Europe, NPIs, vaccination
@article{nokey,
title = {Untangling the changing impact of non-pharmaceutical interventions and vaccination on European COVID-19 trajectories},
author = {Ge, Yong and Zhang, Wen-Bin and Wu, Xilin and Ruktanonchai, Corrine W and Liu, Haiyan and Wang, Jianghao and Song, Yongze and Liu, Mengxiao and Yan, Wei and Yang, Juan and Cleary, Eimear and Qader, Sarchil H. and Atuhaire, Fatumah and Ruktanonchai, Nick W. and Tatem, Andrew J. and Lai Shengjie },
doi = {10.1038/s41467-022-30897-1},
year = {2022},
date = {2022-06-03},
urldate = {2022-06-03},
journal = {Nature Communications},
volume = {13},
issue = {3106},
abstract = {Non-pharmaceutical interventions (NPIs) and vaccination are two fundamental approaches for mitigating the coronavirus disease 2019 (COVID-19) pandemic. However, the real-world impact of NPIs versus vaccination, or a combination of both, on COVID-19 remains uncertain. To address this, we built a Bayesian inference model to assess the changing effect of NPIs and vaccination on reducing COVID-19 transmission, based on a large-scale dataset including epidemiological parameters, virus variants, vaccines, and climate factors in Europe from August 2020 to October 2021. We found that (1) the combined effect of NPIs and vaccination resulted in a 53% (95% confidence interval: 42–62%) reduction in reproduction number by October 2021, whereas NPIs and vaccination reduced the transmission by 35% and 38%, respectively; (2) compared with vaccination, the change of NPI effect was less sensitive to emerging variants; (3) the relative effect of NPIs declined 12% from May 2021 due to a lower stringency and the introduction of vaccination strategies. Our results demonstrate that NPIs were complementary to vaccination in an effort to reduce COVID-19 transmission, and the relaxation of NPIs might depend on vaccination rates, control targets, and vaccine effectiveness concerning extant and emerging variants.},
keywords = {covid-19, Europe, NPIs, vaccination},
pubstate = {published},
tppubtype = {article}
}
Ge, Yong; Liu, Mengxiao; Hu, Shan; Wang, Daoping; Wang, Jinfeng; Wang, Xiaolin; Qader, Sarchil; Cleary, Eimear; Tatem, Andrew J.; Lai, Shengjie
Who and which regions are at high risk of returning to poverty during the COVID-19 pandemic? Journal Article
In: Humanities and Social Sciences Communications, vol. 9, no. 183, 2022.
Abstract | Links | BibTeX | Tags: covid-19
@article{nokey,
title = {Who and which regions are at high risk of returning to poverty during the COVID-19 pandemic?},
author = {Ge, Yong and Liu, Mengxiao and Hu, Shan and Wang, Daoping and Wang, Jinfeng and Wang, Xiaolin and Qader, Sarchil and Cleary, Eimear and Tatem, Andrew J. and Lai, Shengjie},
doi = {https://doi.org/10.1057/s41599-022-01205-5},
year = {2022},
date = {2022-05-25},
urldate = {2022-05-25},
journal = {Humanities and Social Sciences Communications},
volume = {9},
number = {183},
abstract = {Pandemics such as COVID-19 and their induced lockdowns/travel restrictions have a significant impact on people’s lives, especially for lower-income groups who lack savings and rely heavily on mobility to fulfill their daily needs. Taking the COVID-19 pandemic as an example, this study analysed the risk of returning to poverty for low-income households in Hubei Province in China as a result of the COVID-19 lockdown. Employing a dataset including information on 78,931 government-identified poor households, three scenarios were analysed in an attempt to identify who is at high risk of returning to poverty, where they are located, and how the various risk factors influence their potential return to poverty. The results showed that the percentage of households at high risk of returning to poverty (falling below the poverty line) increased from 5.6% to 22% due to a 3-month lockdown. This vulnerable group tended to have a single source of income, shorter working hours, and more family members. Towns at high risk (more than 2% of households returning to poverty) doubled (from 27.3% to 46.9%) and were mainly located near railway stations; an average decrease of 10–50 km in the distance to the nearest railway station increased the risk from 1.8% to 9%. These findings, which were supported by the representativeness of the sample and a variety of robustness tests, provide new information for policymakers tasked with protecting vulnerable groups at high risk of returning to poverty and alleviating the significant socio-economic consequences of future pandemics.},
keywords = {covid-19},
pubstate = {published},
tppubtype = {article}
}
Muchiri, Samuel K.; Muthee, Rose; Kiarie, Hellen; Sitienei, Joseph; Agweyu, Ambrose; Atkinson, Peter M.; Utazi, C. Edson; Tatem, Andrew J.; Alegana, Victor A.
Unmet need for COVID-19 vaccination coverage in Kenya Journal Article
In: Vaccine, vol. 40, no. 13, 2022, ISSN: 0264-410X.
Abstract | Links | BibTeX | Tags: Africa, covid-19, Kenya, travel time, vaccination
@article{nokey,
title = {Unmet need for COVID-19 vaccination coverage in Kenya},
author = {Samuel K. Muchiri and Rose Muthee and Hellen Kiarie and Joseph Sitienei and Ambrose Agweyu and Peter M. Atkinson and C. {Edson Utazi} and Andrew J. Tatem and Victor A. Alegana},
doi = {https://doi.org/10.1016/j.vaccine.2022.02.035},
issn = {0264-410X},
year = {2022},
date = {2022-02-14},
urldate = {2022-02-14},
journal = {Vaccine},
volume = {40},
number = {13},
abstract = {COVID-19 has impacted the health and livelihoods of billions of people since it emerged in 2019. Vaccination for COVID-19 is a critical intervention that is being rolled out globally to end the pandemic. Understanding the spatial inequalities in vaccination coverage and access to vaccination centres is important for planning this intervention nationally. Here, COVID-19 vaccination data, representing the number of people given at least one dose of vaccine, a list of the approved vaccination sites, population data and ancillary GIS data were used to assess vaccination coverage, using Kenya as an example. Firstly, physical access was modelled using travel time to estimate the proportion of population within 1 hour of a vaccination site. Secondly, a Bayesian conditional autoregressive (CAR) model was used to estimate the COVID-19 vaccination coverage and the same framework used to forecast coverage rates for the first quarter of 2022. Nationally, the average travel time to a designated COVID-19 vaccination site (n = 622) was 75.5 min (Range: 62.9 – 94.5 min) and over 87% of the population >18 years reside within 1 hour to a vaccination site. The COVID-19 vaccination coverage in December 2021 was 16.70% (95% CI: 16.66 – 16.74) – 4.4 million people and was forecasted to be 30.75% (95% CI: 25.04 – 36.96) – 8.1 million people by the end of March 2022. Approximately 21 million adults were still unvaccinated in December 2021 and, in the absence of accelerated vaccine uptake, over 17.2 million adults may not be vaccinated by end March 2022 nationally. Our results highlight geographic inequalities at sub-national level and are important in targeting and improving vaccination coverage in hard-to-reach populations. Similar mapping efforts could help other countries identify and increase vaccination coverage for such populations.},
keywords = {Africa, covid-19, Kenya, travel time, vaccination},
pubstate = {published},
tppubtype = {article}
}
Han, Shasha; Zhang, Ting; Lyu, Yan; Lai, Shengjie; Dai, Peixi; Zheng, Jiandong; Yang, Weizhong; Zhou, Xiao-Hua; Feng, Luzhao
Influenza’s plummeting during the COVID-19 pandemic: The roles of mask-wearing, mobility change, and SARS-CoV-2 interference Journal Article
In: Engineering, 2022, ISSN: 2095-8099.
Abstract | Links | BibTeX | Tags: covid-19, influenza, NPIs
@article{nokey,
title = {Influenza’s plummeting during the COVID-19 pandemic: The roles of mask-wearing, mobility change, and SARS-CoV-2 interference},
author = {Shasha Han and Ting Zhang and Yan Lyu and Shengjie Lai and Peixi Dai and Jiandong Zheng and Weizhong Yang and Xiao-Hua Zhou and Luzhao Feng},
doi = {https://doi.org/10.1016/j.eng.2021.12.011},
issn = {2095-8099},
year = {2022},
date = {2022-02-02},
urldate = {2022-02-02},
journal = {Engineering},
abstract = {Seasonal influenza activity typically peaks in the winter months but plummeted globally during the current coronavirus disease 2019 (COVID-19) pandemic. Unraveling lessons from influenza’s unprecedented low profile is critical in informing preparedness for incoming influenza seasons. Here, we explored a country-specific inference model to estimate the effects of mask-wearing, mobility changes (international and domestic), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) interference in China, England, and the United States. We found that a one-week increase in mask-wearing intervention had a percent reduction of 11.3%–35.2% in influenza activity in these areas. The one-week mobility mitigation had smaller effects for the international (1.7%–6.5%) and the domestic community (1.6%–2.8%). In 2020–2021, the mask-wearing intervention alone could decline percent positivity by 13.3–19.8. The mobility change alone could reduce percent positivity by 5.2–14.0, of which 79.8%–98.2% were attributed to the deflected international travel. Only in 2019–2020, SARS-CoV-2 interference had statistically significant effects. There was a reduction in percent positivity of 7.6 (2.4–14.4) and 10.2 (7.2–13.6) in northern China and England, respectively. Our results have implications for understanding how influenza evolves under non-pharmaceutical interventions and other respiratory diseases and will inform health policy and the design of tailored public health measures.},
keywords = {covid-19, influenza, NPIs},
pubstate = {published},
tppubtype = {article}
}
Lai, Shengjie; Li, Zhenlong; Cleary, Eimear; Bondarenko, Maksym; and Tatem, Andrew J
2021, visited: 17.12.2021.
Abstract | Links | BibTeX | Tags: covid-19, vaccination
@online{nokey,
title = {Exploring international travel patterns and connected communities for understanding the spreading risk of VOC Omicron},
author = {Lai, Shengjie and Li, Zhenlong and Cleary, Eimear and Bondarenko, Maksym and and Tatem, Andrew J },
url = {/events/covid_omicron},
year = {2021},
date = {2021-12-17},
urldate = {2021-12-17},
journal = {WorldPop Research},
abstract = {The novel SARS-CoV-2 variant of concern (VOC) Omicron (lineage B.1.1.529), together with four existing VOC variants, has raised serious concerns about the effectiveness of vaccines and the potential for a new wave of the pandemic. This new strain was first detected in in November 2021 in South Africa and among international cases with a travel history from southern African countries. However, community transmission with associated clusters has now been reported in several countries. According to the COVID-19 Weekly Epidemiological Update published by the WHO, a total of 76 countries have reported confirmed cases of the Omicron variant, as of December 14, 2021 },
keywords = {covid-19, vaccination},
pubstate = {published},
tppubtype = {online}
}
Ge, Yong; Zhang, Wen-Bin; Liu, Haiyan; Ruktanonchai, Corrine W; Hu, Maogui; Wu, Xilin; Song, Yongze; Ruktanonchai, Nick W; Yan, Wei; Cleary, Eimear; Feng, Luzhao; Li, Zhongjie; Yang, Weizhong; Liu, Mengxiao; Tatem, Andrew J; Wang, Jin-Feng; and Shengjie Lai,
Impacts of worldwide individual non-pharmaceutical interventions on COVID-19 transmission across waves and space Journal Article
In: International Journal of Applied Earth Observation and Geoinformation, vol. 106, 2021.
Abstract | Links | BibTeX | Tags: covid-19, NPIs
@article{nokey,
title = {Impacts of worldwide individual non-pharmaceutical interventions on COVID-19 transmission across waves and space},
author = {Yong Ge and Wen-Bin Zhang and Haiyan Liu and Corrine W Ruktanonchai and Maogui Hu and Xilin Wu and Yongze Song and Nick W Ruktanonchai and Wei Yan and Eimear Cleary and Luzhao Feng and Zhongjie Li and Weizhong Yang and Mengxiao Liu and Andrew J Tatem and Jin-Feng Wang and and Shengjie Lai},
doi = {https://doi.org/10.1016/j.jag.2021.102649},
year = {2021},
date = {2021-12-13},
urldate = {2021-12-13},
journal = {International Journal of Applied Earth Observation and Geoinformation},
volume = {106},
abstract = {Governments worldwide have rapidly deployed non-pharmaceutical interventions (NPIs) to mitigate the COVID-19 pandemic. However, the effect of these individual NPI measures across space and time has yet to be sufficiently assessed, especially with the increase of policy fatigue and the urge for NPI relaxation in the vaccination era. Using the decay ratio in the suppression of COVID-19 infections and multi-source big data, we investigated the changing performance of different NPIs across waves from global and regional levels (in 133 countries) to national and subnational (in the United States of America [USA]) scales before the implementation of mass vaccination. The synergistic effectiveness of all NPIs for reducing COVID-19 infections declined along waves, from 95.4% in the first wave to 56.0% in the third wave recently at the global level and similarly from 83.3% to 58.7% at the USA national level, while it had fluctuating performance across waves on regional and subnational scales. Regardless of geographical scale, gathering restrictions and facial coverings played significant roles in epidemic mitigation before the vaccine rollout. Our findings have important implications for continued tailoring and implementation of NPI strategies, together with vaccination, to mitigate future COVID-19 waves, caused by new variants, and other emerging respiratory infectious diseases.},
keywords = {covid-19, NPIs},
pubstate = {published},
tppubtype = {article}
}
Li, Juan; Lai, Shengjie; Gao, George F; and Shi, Weifeng
The emergence, genomic diversity and global spread of SARS-CoV-2 Journal Article
In: Nature, vol. 600, pp. 408–418, 2021.
Abstract | Links | BibTeX | Tags: covid-19, Mobility
@article{nokey,
title = {The emergence, genomic diversity and global spread of SARS-CoV-2},
author = {Li, Juan and Lai, Shengjie and Gao, George F and and Shi, Weifeng},
doi = {https://doi.org/10.1038/s41586-021-04188-6},
year = {2021},
date = {2021-12-08},
urldate = {2021-12-08},
journal = {Nature},
volume = {600},
pages = {408–418},
abstract = {Since the first cases of COVID-19 were documented in Wuhan, China in 2019, the world has witnessed a devastating global pandemic, with more than 238 million cases, nearly 5 million fatalities and the daily number of people infected increasing rapidly. Here we describe the currently available data on the emergence of the SARS-CoV-2 virus, the causative agent of COVID-19, outline the early viral spread in Wuhan and its transmission patterns in China and across the rest of the world, and highlight how genomic surveillance, together with other data such as those on human mobility, has helped to trace the spread and genetic variation of the virus and has also comprised a key element for the control of the pandemic. We pay particular attention to characterizing and describing the international spread of the major variants of concern of SARS-CoV-2 that were first identified in late 2020 and demonstrate that virus evolution has entered a new phase. More broadly, we highlight our currently limited understanding of coronavirus diversity in nature, the rapid spread of the virus and its variants in such an increasingly connected world, the reduced protection of vaccines, and the urgent need for coordinated global surveillance using genomic techniques. In summary, we provide important information for the prevention and control of both the ongoing COVID-19 pandemic and any new diseases that will inevitably emerge in the human population in future generations.},
keywords = {covid-19, Mobility},
pubstate = {published},
tppubtype = {article}
}
Shepherd, Harry ER; Atherden, Florence S; Chan, Ho Man Theophilus; Loveridge, Alexandra; Tatem, Andrew J
Domestic and international mobility trends in the United Kingdom during the COVID-19 pandemic: an analysis of facebook data Journal Article
In: International Journal of Health Geographics, vol. 20, no. 46, 2021.
Abstract | Links | BibTeX | Tags: covid-19, Europe, Mobility, NPIs, United Kingdom
@article{nokey,
title = {Domestic and international mobility trends in the United Kingdom during the COVID-19 pandemic: an analysis of facebook data},
author = {Shepherd, Harry ER and Atherden, Florence S and Chan, Ho Man Theophilus and Loveridge, Alexandra and Tatem, Andrew J},
doi = {10.1186/s12942-021-00299-5},
year = {2021},
date = {2021-12-04},
urldate = {2021-12-04},
journal = {International Journal of Health Geographics},
volume = {20},
number = {46},
abstract = {Since early March 2020, the COVID-19 epidemic across the United Kingdom has led to a range of social distancing policies, which resulted in changes to mobility across different regions. An understanding of how these policies impacted travel patterns over time and at different spatial scales is important for designing effective strategies, future pandemic planning and in providing broader insights on the population geography of the country. Crowd level data on mobile phone usage can be used as a proxy for population mobility patterns and provide a way of quantifying in near-real time the impact of social distancing measures on changes in mobility.
Methods
Here we explore patterns of change in densities, domestic and international flows and co-location of Facebook users in the UK from March 2020 to March 2021.
Results
We find substantial heterogeneities across time and region, with large changes observed compared to pre-pademic patterns. The impacts of periods of lockdown on distances travelled and flow volumes are evident, with each showing variations, but some significant reductions in co-location rates. Clear differences in multiple metrics of mobility are seen in central London compared to the rest of the UK, with each of Scotland, Wales and Northern Ireland showing significant deviations from England at times. Moreover, the impacts of rapid changes in rules on international travel to and from the UK are seen in substantial fluctuations in traveller volumes by destination.
Conclusions
While questions remain about the representativeness of the Facebook data, previous studies have shown strong correspondence with census-based data and alternative mobility measures, suggesting that findings here are valuable for guiding strategies.},
keywords = {covid-19, Europe, Mobility, NPIs, United Kingdom},
pubstate = {published},
tppubtype = {article}
}
Methods
Here we explore patterns of change in densities, domestic and international flows and co-location of Facebook users in the UK from March 2020 to March 2021.
Results
We find substantial heterogeneities across time and region, with large changes observed compared to pre-pademic patterns. The impacts of periods of lockdown on distances travelled and flow volumes are evident, with each showing variations, but some significant reductions in co-location rates. Clear differences in multiple metrics of mobility are seen in central London compared to the rest of the UK, with each of Scotland, Wales and Northern Ireland showing significant deviations from England at times. Moreover, the impacts of rapid changes in rules on international travel to and from the UK are seen in substantial fluctuations in traveller volumes by destination.
Conclusions
While questions remain about the representativeness of the Facebook data, previous studies have shown strong correspondence with census-based data and alternative mobility measures, suggesting that findings here are valuable for guiding strategies.
Chen, Qiulan; Rodewald, Lance; Lai, Shengjie; Gao, George F
Rapid and sustained containment of covid-19 is achievable and worthwhile: implications for pandemic response Journal Article
In: BMJ, vol. 375, no. e066169, 2021.
Abstract | Links | BibTeX | Tags: covid-19, NPIs
@article{nokey,
title = {Rapid and sustained containment of covid-19 is achievable and worthwhile: implications for pandemic response},
author = {Chen, Qiulan and Rodewald, Lance and Lai, Shengjie and Gao, George F},
doi = {https://doi.org/10.1136/BMJ-2021-066169},
year = {2021},
date = {2021-12-02},
urldate = {2021-12-02},
journal = {BMJ},
volume = {375},
number = {e066169},
abstract = {In the 20 months since the World Health Organization declared covid-19 to be a pandemic, more than 250 million cases have been confirmed. More than 5 million deathshave occurred disproportionately by country, with 10% of countries reporting 80% of cases.1 In a new pandemic, with no vaccines prepared, non-pharmaceutical interventions are the only response. In the first year of the covid-19 pandemic, several countries that aimed to completely interrupt community transmission—China, Singapore, Australia, and New Zealand—achieved and maintained containment.23 Here, we analyse China’s containment strategy before vaccine roll-out and describe measures for initial and sustained containment and benefits for the country.
Containment of covid-19 means stopping transmission of SARS-CoV-2.4 Core measures of containment include actively finding infected people and treatment in isolation, close contact tracing and quarantine, and restrictions of travel from areas with community transmission. Additional measures that reduce transmission include stay at home orders, cancellation of mass gatherings, closing schools, and use of personal protection measures, such as hand hygiene, respiratory etiquette, keeping at least 1 m distance, and mask wearing.
Sustained containment is maintaining elimination of SARS-CoV-2 by completely stopping all externally introduced outbreaks—a policy of “zero tolerance for local transmission (zero covid).” Responses to an outbreak are based on an assessment of the epidemic risk and use the same measures as those used for the initial containment. These measures are augmented by strict border protection to minimise the number of imported outbreaks and by surveillance for infection using highly sensitive, routine polymerase chain reaction (PCR). Table 1 shows the initial and sustained containment measures based on assessment of the risk of epidemic.
},
keywords = {covid-19, NPIs},
pubstate = {published},
tppubtype = {article}
}
Containment of covid-19 means stopping transmission of SARS-CoV-2.4 Core measures of containment include actively finding infected people and treatment in isolation, close contact tracing and quarantine, and restrictions of travel from areas with community transmission. Additional measures that reduce transmission include stay at home orders, cancellation of mass gatherings, closing schools, and use of personal protection measures, such as hand hygiene, respiratory etiquette, keeping at least 1 m distance, and mask wearing.
Sustained containment is maintaining elimination of SARS-CoV-2 by completely stopping all externally introduced outbreaks—a policy of “zero tolerance for local transmission (zero covid).” Responses to an outbreak are based on an assessment of the epidemic risk and use the same measures as those used for the initial containment. These measures are augmented by strict border protection to minimise the number of imported outbreaks and by surveillance for infection using highly sensitive, routine polymerase chain reaction (PCR). Table 1 shows the initial and sustained containment measures based on assessment of the risk of epidemic.