Effectiveness of different types and levels of social distancing measures: a scoping review of global evidence from earlier stage of COVID-19 pandemic

From node to network: weaving a global perspective on efficacy and costs of non-pharmaceutical interventions

Non-pharmaceutical intervention (NPI) policies, ranging from mild measures to total isolation, were implemented worldwide during the COVID-19 pandemic. We adopt a systematic approach to guide policymakers in deploying NPI policies to mitigate the pandemic's effects while balancing their social and economic impacts. Our results show that each NPI has an optimal duration, beyond which its effectiveness plateaus. Stricter policies require longer durations, and when sustained for the optimal period, earlier implementation is more effective. However, when this duration is unattainable, timing becomes critical, as both early and late implementation reduce efficacy. Stringent policies with insufficient durations may perform worse than less restrictive measures applied over the same period, and an NPI policy aimed at minimizing overall healthcare burden under a fixed policy duration may significantly intensify peak-time strains. Finally, as the virus becomes more transmissible and less lethal, the effectiveness gap between stringent and less restrictive policies narrows, with targeted interventions for vulnerable groups outperforming universal strict measures.

Mental health variables affecting Quality of Life (QOL) among healthcare workers during the COVID-19 pandemic in Jazan City, Saudi Arabia

Background

Health workers directly involved in the diagnosis, treatment, and care of patients with COVID-19 are at risk of developing mental health symptoms.

Objective

The study aimed to assess the quality of life (QoL) of healthcare workers at Prince Mohammed bin Nasser Tertiary Hospital in Jazan during the COVID-19 pandemic, with a focus on the relationship between QoL and stress, anxiety, and depression. Pandemic.

Methods

This was a cross-sectional study conducted among healthcare workers at Prince Mohammed bin Nasser Hospital in the Jazan. The study included a sample of 352 healthcare workers. Data was collected through a self-administered questionnaire pertaining to sociodemographic characteristics and the 21-item Depression Anxiety Stress Scale questionnaire, SF-36, for QoL. Descriptive statistics, frequencies, and percentages were used. A chi-squared test was performed to compare categorical data. A one-way ANOVA was performed to compare the effect of disorder variables on QoL. Multiple linear regression analyses were carried out to discern the differences between the different groups of participants in QoL measures.

Results

Our results showed a poor QoL among those with a chronic disease (p = 0.002), who worked in the COVID-19 department (p = 0.030) and those who experienced the death of relatives or friends due to COVID-19 (p = 0.003).

Conclusion

Healthcare workers, particularly those with chronic diseases or who had lost relatives to COVID-19, exhibited significantly lower QoL levels, especially those working directly in COVID-19 departments.

More adverse childhood experiences are associated with increased social thinning and severe psychological distress

Adverse childhood experiences have been linked to psychopathology due to reduced social networks or social thinning. However, evidence of the temporal associations between adverse childhood experiences, social networks, and psychopathology was lacking, as few studies assessed social networks repeatedly. Further, their underlying neurocognitive and biological mechanisms related to hypervigilance and inflammation remain unclear. This study aimed to clarify these associations using a three-wave population-based cohort study during the COVID-19 pandemic (n = 465), where we leveraged repeated social network assessments. Self-reported questionnaires assessed adverse childhood experiences, social network size and diversity, psychological distress, and hypervigilance regarding COVID-19. Blood tests were conducted to measure inflammation markers. Individuals with more adverse childhood experiences demonstrated lesser increases in their social networks than those without adverse childhood experiences. Decreased network sizes were associated with severe psychological distress, but this association did not remain after adjusting for baseline distress. On the other hand, reduced network diversities were associated with increased psychological distress. We did not find any paths through hypervigilance regarding COVID-19 and inflammation that explain associations between adverse childhood experiences, social thinning, and psychological distress. These findings emphasize the significant social network changes in the associations between adverse childhood experiences and psychopathology.

[Effect of non-pharmacological preventive measures on the incidence of respiratory and gastrointestinal pathologies]

OBJECTIVE

The use of non-pharmacological preventive measures during the COVID-19 pandemic has helped to reduce the incidence of multiple airborne or contact diseases. The objective of this paper was to evaluate the impact that all preventive measures have had on the transmission of different microorganisms, both by respiratory and contact transmission.

METHODS

We compared the incidence of different infectious episodes coded with the CIAP-2 code (International Classification of Primary Care second edition of the WONCA International Classification Committee) collected from the computerized history of primary care, both with respiratory tract and digestive tract involvement, in the period from March 2018 to February 2020 (pre-pandemic period) and from March 2020 to February 2022 (pandemic period). The data corresponded to the entire region, with an estimated average population for the four years of 650,000 people. The statistical treatment of the data consisted of a descriptive analysis with the calculation of absolute values and percentages. Rates were calculated and compared using data provided by the National Institute of Statistics as a denominator. The P was obtained by statistical comparison by the exact method. A comparison of rates was made.

RESULTS

The incidence in the number of CIAP-2 episodes studied, both corresponding to respiratory and gastrointestinal pathologies, comparing the period March 2018-February 2020 with the period March 2020-February 2022 decreased by 65.81%, from 534,439 cases to 182,707.

CONCLUSIONS

The preventive measures applied during the pandemic produce a significant decrease in pathology involving the respiratory or the digestive tract.

Assessing the relationship between delay discounting and decisions to engage in various protective behaviors during COVID-19

Research suggests that discounting of delayed rewards (i.e., tendency to choose smaller immediate rewards over large later rewards) is a promising target of intervention to encourage compliance with public health measures (PHM), such as vaccination compliance. The effects of delay discounting, however, may differ across the types of PHMs, given that the benefits of vaccination, unlike other PHMs (physical distancing, handwashing, and mask-wearing), are more temporally delayed. Here, we examined whether delay discounting predicts engaging in COVID-19 PHMs in approximately 7,000 participants recruited from 13 countries in June-August 2021. After controlling for demographic and distress variables, delay discounting was a negative predictor of vaccination, but a positive predictor of physical distancing (when restrictions are in place) and handwashing. There was no significant association between delay discounting and frequency of mask-wearing. It is possible that increasing vaccination compliance may require greater emphasis on future benefits of vaccination, whereas promotion of physical distancing and hand hygiene may require greater focus on the present moment. Further research is needed to investigate the nature of this relationship and its implications for public health messaging.

Non-pharmaceutical interventions to reduce COVID-19 transmission in the UK: a rapid mapping review and interactive evidence gap map

BACKGROUND

Non-pharmaceutical interventions (NPIs) were crucial in the response to the COVID-19 pandemic, although uncertainties about their effectiveness remain. This work aimed to better understand the evidence generated during the pandemic on the effectiveness of NPIs implemented in the UK.

METHODS

We conducted a rapid mapping review (search date: 1 March 2023) to identify primary studies reporting on the effectiveness of NPIs to reduce COVID-19 transmission. Included studies were displayed in an interactive evidence gap map.

RESULTS

After removal of duplicates, 11 752 records were screened. Of these, 151 were included, including 100 modelling studies but only 2 randomized controlled trials and 10 longitudinal observational studies.Most studies reported on NPIs to identify and isolate those who are or may become infectious, and on NPIs to reduce the number of contacts. There was an evidence gap for hand and respiratory hygiene, ventilation and cleaning.

CONCLUSIONS

Our findings show that despite the large number of studies published, there is still a lack of robust evaluations of the NPIs implemented in the UK. There is a need to build evaluation into the design and implementation of public health interventions and policies from the start of any future pandemic or other public health emergency.

Treating COVID-19 with Medicinal Plants: Is It Even Conceivable? A Comprehensive Review

In 2020, severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) challenged the world with a global outbreak that led to millions of deaths worldwide. Coronavirus disease 2019 (COVID-19) is the symptomatic manifestation of this virus, which can range from flu-like symptoms to utter clinical complications and even death. Since there was no clear medicine that could tackle this infection or lower its complications with minimal adverse effects on the patients' health, the world health organization (WHO) developed awareness programs to lower the infection rate and limit the fast spread of this virus. Although vaccines have been developed as preventative tools, people still prefer going back to traditional herbal medicine, which provides remarkable health benefits that can either prevent the viral infection or limit the progression of severe symptoms through different mechanistic pathways with relatively insignificant side effects. This comprehensive review provides scientific evidence elucidating the effect of 10 different plants against SARS-CoV-2, paving the way for further studies to reconsider plant-based extracts, rich in bioactive compounds, into more advanced clinical assessments in order to identify their impact on patients suffering from COVID-19.

Emerging and re-emerging pediatric viral diseases: a continuing global challenge

The twenty-first century has been marked by a surge in viral epidemics and pandemics, highlighting the global health challenge posed by emerging and re-emerging pediatric viral diseases. This review article explores the complex dynamics contributing to this challenge, including climate change, globalization, socio-economic interconnectedness, geopolitical tensions, vaccine hesitancy, misinformation, and disparities in access to healthcare resources. Understanding the interactions between the environment, socioeconomics, and health is crucial for effectively addressing current and future outbreaks. This scoping review focuses on emerging and re-emerging viral infectious diseases, with an emphasis on pediatric vulnerability. It highlights the urgent need for prevention, preparedness, and response efforts, particularly in resource-limited communities disproportionately affected by climate change and spillover events. Adopting a One Health/Planetary Health approach, which integrates human, animal, and ecosystem health, can enhance equity and resilience in global communities. IMPACT: We provide a scoping review of emerging and re-emerging viral threats to global pediatric populations This review provides an update on current pediatric viral threats in the context of the COVID-19 pandemic This review aims to sensitize clinicians, epidemiologists, public health practitioners, and policy stakeholders/decision-makers to the role these viral diseases have in persistent pediatric morbidity and mortality.

Impacts of public health and social measures on COVID-19 in Europe: a review and modified Delphi technique

Introduction

The emergence of the COVID-19 pandemic in early 2020 led countries to implement a set of public health and social measures (PHSMs) attempting to contain the spread of the SARS-CoV-2 virus. This study aims to review the existing literature regarding key results of the PHSMs that were implemented, and to identify the PHSMs considered to have most impacted the epidemiological curve of COVID-19 over the last years during different stages of the pandemic.

Methods

The PHSM under study were selected from the Oxford COVID-19 Government Response Tracker (OxCGRT), supplemented by topics presented during the Rapid Exchange Forum (REF) meetings in the scope of the Population Health Information Research Infrastructure (PHIRI) project (H2020). The evidence- based review was conducted using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines to identify which reviews have already been published about each PHSMs and their results. In addition, two modified Delphi panel surveys were conducted among subject matter experts from 30 European countries to uphold the results found.

Results

There were 3,212 studies retrieved from PubMed, 162 full texts assessed for eligibility and 35 included in this PHSMs summary. The measures with clearest evidence on their positive impact from the evidence-based review include social distancing, hygiene measures, mask measures and testing policies. From the modified Delphi panel, the PHSMs considered most significant in the four periods analyzed were case isolation at home, face coverings, testing policy, and social distancing, respectively.

Discussion

The evidence found has significant implications for both researchers and policymakers. The study of PHSMs' impact on COVID-19 illustrates lessons learned for future pan- and epidemics, serving as a contribution to the health systems resilience discussion. These lessons, drawn from both the available scientific evidence and the perspectives of relevant subject matter experts, should also be considered in educational and preparedness programs and activities in the public health space.

Nonpharmaceutical interventions for managing SARS-CoV-2

PURPOSE OF REVIEW

Initial response strategies to the COVID-19 pandemic were heavily reliant on nonpharmaceutical interventions (NPIs), a set of measures implemented to slow or even stop the spread of infection. Here, we reviewed key measures used during the COVID-19 pandemic.

RECENT FINDINGS

Some NPIs were successful in reducing the transmission of SARS-CoV-2. Personal protective measures such as face masks were widely used, and likely had some effect on transmission. The development and production of rapid antigen tests allowed self-diagnosis in the community, informing isolation and quarantine measures. Community-wide measures such as school closures, workplace closures and complete stay-at-home orders were able to reduce contacts and prevent transmission. They were widely used in the pandemic and contributed to reduce transmission in the community; however, there were also negative unintended consequences in the society and economy.

SUMMARY

NPIs slowed the spread of SARS-CoV-2 and are essential for pandemic preparedness and response. Understanding which measures are more effective at reducing transmission with lower costs is imperative.

Complexity of Government response to COVID-19 pandemic: a perspective of coupled dynamics on information heterogeneity and epidemic outbreak

This study aims at modeling the universal failure in preventing the outbreak of COVID-19 via real-world data from the perspective of complexity and network science. Through formalizing information heterogeneity and government intervention in the coupled dynamics of epidemic and infodemic spreading, first, we find that information heterogeneity and its induced variation in human responses significantly increase the complexity of the government intervention decision. The complexity results in a dilemma between the socially optimal intervention that is risky for the government and the privately optimal intervention that is safer for the government but harmful to the social welfare. Second, via counterfactual analysis against the COVID-19 crisis in Wuhan, 2020, we find that the intervention dilemma becomes even worse if the initial decision time and the decision horizon vary. In the short horizon, both socially and privately optimal interventions agree with each other and require blocking the spread of all COVID-19-related information, leading to a negligible infection ratio 30 days after the initial reporting time. However, if the time horizon is prolonged to 180 days, only the privately optimal intervention requires information blocking, which would induce a catastrophically higher infection ratio than that in the counterfactual world where the socially optimal intervention encourages early-stage information spread. These findings contribute to the literature by revealing the complexity incurred by the coupled infodemic-epidemic dynamics and information heterogeneity to the governmental intervention decision, which also sheds insight into the design of an effective early warning system against the epidemic crisis in the future.

Impact of insomnia on mental status among chronic disease patients during Covid-19 pandemic

Background

The Coronavirus disease (Covid-19) 2019 pandemic had a serious impact on the mental health of individuals globally. A lack of psychological well-being on the part of individuals with chronic diseases might increase the risk of developing symptoms such as insomnia, depression, and anxiety.

Objectives

The aim of this study is to evaluate the prevalence of insomnia, depression, and anxiety among patients with chronic disease during the Covid-19 pandemic in Oman.

Methods

This is a web-based cross-sectional study conducted between June 2021 and September 2021. Insomnia was assessed by using the Insomnia Severity Index (ISI), while depression and anxiety were measured using the Hospital Anxiety and Depression Scale (HADS).

Results

Of the 922 chronic disease patients who participated, 77% (n = 710) reported insomnia, while the mean score for the ISI was11.38 (SD 5.82). Depression and anxiety were prevalent among the participants with 47% and 63% respectively. The participants' mean with regard to the sleep duration items was 7.04 (SD = 1.59) hours per night, whereas the mean in terms of sleep latency was 38.18 minutes (SD = 31.81). Logistic regression analysis revealed that insomnia was positively associated with depression and anxiety.

Conclusions

This study demonstrated that chronic disease patients had a high prevalence of insomnia during the Covid-19 pandemic. Psychological support is recommended in order to help such patients reduce the level of insomnia. Furthermore, a routine assessment of levels of insomnia, depression and anxiety is essential, in order to help identify appropriate intervention and management measures.

Scientific Misinformation and Mistrust of COVID-19 Preventive Measures among the UK Population: A Pilot Study

The popularisation of complex biomedical concepts brought about by COVID-19 has led to the rapid proliferation and diffusion of scientific misinformation, particularly among individuals with inadequate levels of scientific and digital literacy. A cross-sectional online survey of a UK population sample was conducted to address three key aims: to verify whether there is a correlation between participants' belief in false information around COVID-19 and adherence to preventive measures; to investigate whether participants' scientific misinformation and preventive behaviour are associated with their demographic characteristics; and to evaluate whether participants' scientific misinformation and preventive behaviour can predict their likelihood of having contracted COVID-19. Non-parametric data analysis highlighted a strong negative correlation between participants' belief in misinformation and their trust in preventive measures. Both variables were significantly associated with participants' education levels, but not with their religious beliefs. Remarkably, neither science misinformation levels nor the trust in preventive measures were statistically associated with the likelihood of having contracted COVID-19. Taken together, these findings reinforce the urgency of ensuring that the population is equipped with adequate scientific literacy to enable them to evaluate the reliability of scientific information and recognise the importance of individual preventive behaviours to minimise community spread of infectious diseases.

SARS-CoV-2 in brief: from virus to prevention

The recent outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), ahighly transmissible virus with a likely animal origin, has posed major and unprecedentedchallenges to millions of lives across the affected nations of the world. This outbreak firstoccurred in China, and despite massive regional and global attempts shortly thereafter, itspread to other countries and caused millions of deaths worldwide. This review presents keyinformation about the characteristics of SARS-CoV-2 and its associated disease (namely,coronavirus disease 2019) and briefly discusses the origin of the virus. Herein, we also brieflysummarize the strategies used against viral spread and transmission.

Place of distancing measures in containing epidemics: a scoping review

Distancing is one of the barrier measures in mitigating epidemics. We aimed to investigate the typology, effectiveness, and side effects of distancing rules during epidemics. Electronic searches were conducted on MEDLINE, PubMed in April 2020, using Mesh-Terms representing various forms of distancing ('social isolation', 'social distancing', 'quarantine') combining with 'epidemics'. PRISMA-ScR statement was consulted to report this review. A total of 314 titles were identified and 93 were finally included. 2009 influenza A and SARS-CoV-2 epidemics were the most studied. Distancing measures were mostly classified as case-based and community-based interventions. The combination of distancing rules, like school closure, home working, isolation and quarantine, has proven to be effective in reducing R0 and flattening the epidemic curve, also when initiated early at a high rate and combined with other non-pharmaceutical interventions. Epidemiological and modeling studies showed that Isolation and quarantine in the 2009 Influenza pandemic were effective measures to decrease attack rate also with high level of compliance but there was an increased risk of household transmission. lockdown was also effective to reduce R0 from 2.6 to 0.6 and to increase doubling time from 2 to 4 days in the covid-19 pandemic. The evidence for school closure and workplace distancing was moderate as single intervention. Psychological disorder, unhealthy behaviors, disruption of economic activities, social discrimination, and stigmatization were the main side effects of distancing measures. Earlier implementation of combined distancing measures leads to greater effectiveness in containing outbreaks. Their indication must be relevant and based on evidence to avoid adverse effects on the community. These results would help decision-makers to develop response plans based on the required experience and strengthen the capacity of countries to fight against future epidemics. Mesh words: Physical Distancing, Quarantine, Epidemics, Public Health, Scoping Review.

Emotional Impact and Perception of Support in Nursing Home Residents during the COVID-19 Lockdown: A Qualitative Study

Social isolation measures implemented in nursing homes during the COVID-19 pandemic generated occupational imbalance, discomfort, and mental health impairment in residents. We aimed to analyze the lived experience of elderly nursing home residents during the lockdown and social contact restrictions resulting from the COVID-19 pandemic.

METHODS

Exploratory qualitative study. Information was collected through in-depth interviews and field notes. An inductive thematic analysis was performed and international recommendations for the development of qualitative studies were followed.

RESULTS

Twenty-four participants residing in nursing homes were included. Two main themes were identified: (1) emotional impact of the experience of COVID-19 lockdown (subthemes: experience of contradictory feelings; illness and death; importance of routine; feeling busy; and role of religious beliefs); and (2) support as a therapeutic tool (subthemes: family support; peer support; and professional support).

CONCLUSION

Social restrictions by COVID-19 caused significant changes in residents' occupations and routines, producing fear, loneliness, and abandonment of desired occupations; however, very important supports were also identified that helped to overcome the lockdown, such as social support, spirituality, and gratitude.

Patient Self-Performed Point-of-Care Ultrasound: Using Communication Technologies to Empower Patient Self-Care

Point-of-Care ultrasound (POCUS) is an invaluable tool permitting the understanding of critical physiologic and anatomic details wherever and whenever a patient has a medical need. Thus the application of POCUS has dramatically expanded beyond hospitals to become a portable user-friendly technology in a variety of prehospital settings. Traditional thinking holds that a trained user is required to obtain images, greatly handicapping the scale of potential improvements in individual health assessments. However, as the interpretation of ultrasound images can be accomplished remotely by experts, the paradigm wherein experts guide novices to obtain meaningful images that facilitate remote care is being embraced worldwide. The ultimate extension of this concept is for experts to guide patients to image themselves, enabling secondary disease prevention, home-focused care, and self-empowerment of the individual to manage their own health. This paradigm of remotely telementored self-performed ultrasound (RTMSPUS) was first described for supporting health care on the International Space Station. The TeleMentored Ultrasound Supported Medical Interventions (TMUSMI) Research Group has been investigating the utility of this paradigm for terrestrial use. The technique has particular attractiveness in enabling surveillance of lung health during pandemic scenarios. However, the paradigm has tremendous potential to empower and support nearly any medical question poised in a conscious individual with internet connectivity able to follow the directions of a remote expert. Further studies and development are recommended in all areas of acute and chronic health care.

Simulating the Environmental Spread of SARS-CoV-2 via Cough and the Effect of Personal Mitigations

Background: A cough is known to transmit an aerosol cloud up to 2 m. During the COVID-19 pandemic of 2020 the United Kingdom’s National Health Service (NHS), other UK government agencies and the World Health Organization (WHO) advised people to cough into their elbows. It was thought that this would reduce viral spread and protect the public. However, there is limited peer reviewed evidence to support this. Objectives: To determine if cough related interventions reduce environmental contamination, protecting members of the public from infection. Methods: Scientists and engineers at the Health and Safety Executive (HSE) laboratory used a human cough simulator that provided a standardised cough challenge using a solution of simulated saliva and a SARS-CoV-2 surrogate virus; Phi6. Pseudomonas syringae settle plates were used to detect viable Phi6 virus following a simulated cough into a 4 × 4 m test chamber. The unimpeded pattern of contamination was compared to that when a hand or elbow was placed over the mouth during the cough. High speed back-lit video was also taken to visualise the aerosol dispersion. Results and Discussion: Viable virus spread up to 2 m from the origin of the cough outwards in a cloud. Recommended interventions, such as putting a hand or elbow in front of the mouth changed the pattern of cough aerosol dispersion. A hand deflected the cough to the side, protecting those in front from exposure, however it did not prevent environmental contamination. It also allowed for viral transfer from the hand to surfaces such as door handles. A balled fist in front of the mouth did not deflect the cough. Putting an elbow in front of the mouth deflected the aerosol cloud to above and below the elbow, but would not have protected any individuals standing in front. However, if the person coughed into a sleeved elbow more of the aerosol seemed to be absorbed. Coughing into a bare elbow still allowed for transfer to the environment if people touched the inside of their elbow soon after coughing. Conclusions: Interventions can change the environmental contamination pattern resulting from a human cough but may not reduce it greatly.

Parental Perspectives of the Impact of COVID-19 Lockdown on Food-Related Behaviors: Systematic Review

Home confinement during the COVID-19 pandemic has been accompanied by dramatic changes in household food dynamics that can significantly influence health. This systematic literature review presents parental perspectives of the impact of COVID-19 lockdown (up to 30 June 2022) on food preparation and meal routines, as well as other food-related behaviors, capturing both favorable and unfavorable changes in the household food environment. Themes and trends are identified and associations with other lifestyle factors are assessed. Overall, families enjoyed more time together around food, including planning meals, cooking, and eating together. Eating more diverse foods and balanced home-cooked meals (e.g., fresh fruit and vegetables) was combined with overeating and increased snacking (e.g., high-calorie snacks, desserts, and sweets), as parents became more permissive towards food; however, food insecurity increased among families with the lowest income. Adoption of meal planning skills and online shopping behavior emerged alongside behaviors aimed at self-sufficiency, such as bulk purchasing and stockpiling of non-perishable processed foods. These results are an important first step in recognizing how this pandemic may be affecting the family food environment, including low-income families. Future obesity prevention and treatment initiatives, but also ongoing efforts to address food management, parental feeding practices, and food insecurity, can account for these changes moving forward.

Assessing Public Health and Social Measures Against COVID-19 in Japan From March to June 2021

Background

Public health and social measures (PHSM) against COVID-19 in Japan involve requesting the public to voluntarily reduce social contact; these measures are not legally binding. The effectiveness of such PHSM has been questioned with emergence of the SARS-CoV-2 Alpha variant (B.1.1.7), which exhibited elevated transmissibility.

Materials and Methods

We investigated the epidemic dynamics during the fourth epidemic wave in Japan from March to June 2021 involving pre-emergency measures and declaration of a state of emergency (SoE). We estimated the effective reproduction number (R_t) before and after these interventions, and then analyzed the relationship between lower R_t values and each PHSM.

Results

With implementation of pre-emergency measures (PEM) in 16 prefectures, the R_t was estimated to be < 1 in six prefectures; its average relative reduction ranged from 2 to 19%. During the SoE, 8 of 10 prefectures had an estimated R_t < 1, and the average relative reduction was 26%–39%. No single intervention was identified that uniquely resulted in an R_t value < 1.

Conclusion

An SoE can substantially reduce the R_t and may be required to curb a surge in cases caused by future SARS-CoV-2 variants of concern with elevated transmissibility. More customized interventions did not reduce the R_t value to < 1 in this study, but that may be partly attributable to the greater transmissibility of the Alpha variant.