IoT in Elementary School for Everyone - A Research Plan.

We propose a tentative research plan to increase students' mental health in elementary schools by implementing Internet of Things (IoT) technology. The research plan should answer how to support students' mental health using IoT solutions and the critical factors influencing testbeds for IoT solutions with the previously mentioned purpose. Our intended research method is Design Science, which we plan to use stepwise.

Evaluation of Trends in Homeschooling Rates After Elimination of Nonmedical Exemptions to Childhood Immunizations in California, 2012-2020.

Introduction: In 2015, California passed Senate Bill No. 277 (SB 277) and became the first state in more than 30 years to eliminate nonmedical exemptions to mandatory childhood immunizations for school entry. One concern that emerged was that the law created an incentive for parents to remove children from brick-and-mortar schools to bypass the immunization requirements. Objective: To assess the trends in homeschooling rates after the elimination of nonmedical exemptions to the requirement of childhood immunizations for school entry. Design, Setting, and Participants: This preintervention-postintervention cross-sectional study calculated homeschooling rates as the number of students in kindergarten through grade 8 (K-8) enrolled through each of California's 3 homeschooling mechanisms (independent study program, private school affidavit, and private school satellite program) divided by all K-8 students enrolled in the same academic year. Data on homeschooling rates were obtained from the California Department of Education. Interrupted time series analyses were conducted using a linear regression model in which the outcome variable was the percentage of students enrolled in a homeschool program before and after SB 277. Data were collected and analyzed from October 3, 2012, to October 2, 2019. Intervention: Passage of SB 277, which eliminated nonmedical exemptions to childhood immunizations for school entry. Main Outcomes and Measures: Homeschooling rates for K-8 students. Results: Among the students included in the analysis, the homeschooling enrollment for K-8 students in California increased from 35 122 students (0.8%) during the 2012-2013 school year to 86 574 students (1.9%) during the 2019-2020 school year; however, the implementation of SB 277 was not associated with an increase in the percentage of students enrolled in homeschooling programs in California beyond the secular trend. The increase in homeschooling was greatest for the lower grade levels: kindergarten homeschooling enrollment increased from 2068 students (0.4%) in the 2012-2013 school year to 10 553 students (1.9%) in the 2019-2020 school year, whereas the grade 8 homeschool enrollment rate increased from 5146 students (1.0%) in the 2012-2013 school year to 10 485 students (2.0%) in the 2019-2020 school year. Independent study programs accounted for 20 149 students (45.3%) of homeschooling enrollment, private school affidavits accounted for 19 333 students (43.5%), and private school satellite programs accounted for 4935 students (11.1%) during the 2015-2016 school year. Conclusions and Relevance: The findings of this study suggest that legislative action to limit nonmedical exemptions for compulsory vaccination for school entry is not associated with removal of students from classroom-based instruction in brick-and-mortar institutions.

Learning to think critically about health using digital technology in Ugandan lower secondary schools: A contextual analysis.

INTRODUCTION: The world is awash with claims about the effects of health interventions. Many of these claims are untrustworthy because the bases are unreliable. Acting on unreliable claims can lead to waste of resources and poor health outcomes. Yet, most people lack the necessary skills to appraise the reliability of health claims. The Informed Health Choices (IHC) project aims to equip young people in Ugandan lower secondary schools with skills to think critically about health claims and to make good health choices by developing and evaluating digital learning resources. To ensure that we create resources that are suitable for use in Uganda's secondary schools and can be scaled up if found effective, we conducted a context analysis. We aimed to better understand opportunities and barriers related to demand for the resources, how the learning content overlaps with existing curriculum and conditions in secondary schools for accessing and using digital resources, in order to inform resource development. METHODS: We used a mixed methods approach and collected both qualitative and quantitative data. We conducted document analyses, key informant interviews, focus group discussions, school visits, and a telephone survey regarding information communication and technology (ICT). We used a nominal group technique to obtain consensus on the appropriate number and length of IHC lessons that should be planned in a school term. We developed and used a framework from the objectives to code the transcripts and generated summaries of query reports in Atlas.ti version 7. FINDINGS: Critical thinking is a key competency in the lower secondary school curriculum. However, the curriculum does not explicitly make provision to teach critical thinking about health, despite a need acknowledged by curriculum developers, teachers and students. Exam oriented teaching and a lack of learning resources are additional important barriers to teaching critical thinking about health. School closures and the subsequent introduction of online learning during the COVID-19 pandemic has accelerated teachers' use of digital equipment and learning resources for teaching. Although the government is committed to improving access to ICT in schools and teachers are open to using ICT, access to digital equipment, unreliable power and internet connections remain important hinderances to use of digital learning resources. CONCLUSIONS: There is a recognized need for learning resources to teach critical thinking about health in Ugandan lower secondary schools. Digital learning resources should be designed to be usable even in schools with limited access and equipment. Teacher training on use of ICT for teaching is needed.

Sharp increase in inequality in education in times of the COVID-19-pandemic.

The COVID-19-pandemic forced many countries to close schools abruptly in the spring of 2020. These school closures and the subsequent period of distance learning has led to concerns about increasing inequality in education, as children from lower-educated and poorer families have less access to (additional) resources at home. This study analyzes differences in declines in learning gains in primary education in the Netherlands for reading, spelling and math, using rich data on standardized test scores and register data on student and parental background for almost 300,000 unique students. The results show large inequalities in the learning loss based on parental education and parental income, on top of already existing inequalities. The results call for a national focus on interventions specifically targeting vulnerable students.

Menstrual health and factors associated with school absence among secondary school girls in Luang Prabang Province, Lao People's Democratic Republic: A cross-sectional study.

In Lao People's Democratic Republic (Lao PDR), information on school sanitation and menstrual health among secondary school girls is limited. This study aimed to explore knowledge and practices surrounding menstrual health and to identify factors associated with school absence due to menstruation among secondary school girls in Lao PDR. The study involved 1,366 girls from grade 9 to grade 12 in six secondary schools in Luang Prabang Province. Data on socio-demographics and menstrual health of the girls and data on school toilets was collected. Logistic regression analysis was performed to identify the factors associated with school absence due to menstruation. The mean age was 15.8 years old. The average age of menarche was 12.9 years old. Of 1,366 girls, 64.6% were shocked or ashamed when they reached menarche and 31.8% had been absent from school due to menstruation in the six months before this study was conducted. Factors associated with school absence due to menstruation were age ≥ 16 years old (AOR = 1.79, 95% CI 1.37-2.34), higher income (AOR = 2.38, 95% CI 1.16-4.87), menstrual anxiety (AOR = 1.55, 95% CI 1.09-2.20), using painkillers (AOR = 4.79, 95% CI 2.96-7.76) and other methods (AOR = 2.82, 95% CI 1.86-4.28) for dysmenorrhea, and disposing used pads in places other than the school's waste bins (AOR = 1.34, 95% CI 1.03-1.75). Living with relatives (AOR = 0.64, 95% CI 0.43-0.95) and schools outside the city (AOR = 0.59, 95% CI 0.38-0.90) were significantly less associated with school absence. Although the association between school toilets and school absence was not examined, the results of this study suggest that school toilets should be gender-separated and equipped with waste bins in the toilet. Furthermore, menstrual education should start at elementary schools and teacher training on menstrual health should be promoted.

Food Allergy Guidelines for Schools and Childcare Facilities.

Among controversial new recommendations: doing away with categorical food bans.

Children's mental and behavioral health, schooling, and socioeconomic characteristics during school closure in France due to COVID-19: the SAPRIS project.

COVID-19 limitation strategies have led to widespread school closures around the world. The present study reports children's mental health and associated factors during the COVID-19 school closure in France in the spring of 2020. We conducted a cross-sectional analysis using data from the SAPRIS project set up during the COVID-19 pandemic in France. Using multinomial logistic regression models, we estimated associations between children's mental health, children's health behaviors, schooling, and socioeconomic characteristics of the children's families. The sample consisted of 5702 children aged 8-9 years, including 50.2% girls. In multivariate logistic regression models, children's sleeping difficulties were associated with children's abnormal symptoms of both hyperactivity-inattention (adjusted Odds Ratio (aOR) 2.05; 95% Confidence Interval 1.70-2.47) and emotional symptoms (aOR 5.34; 95% CI 4.16-6.86). Factors specifically associated with abnormal hyperactivity/inattention were: male sex (aOR 2.29; 95% CI 1.90-2.76), access to specialized care prior to the pandemic and its suspension during school closure (aOR 1.51; 95% CI 1.21-1.88), abnormal emotional symptoms (aOR 4.06; 95% CI 3.11-5.29), being unschooled or schooled with assistance before lockdown (aOR 2.13; 95% CI 1.43-3.17), and tutoring with difficulties or absence of a tutor (aOR 3.25; 95% CI 2.64-3.99; aOR 2.47; 95% CI 1.48-4.11, respectively). Factors associated with children's emotional symptoms were the following: being born pre-term (aOR 1.34; 95% CI 1.03-1.73), COVID-19 cases among household members (aOR 1.72; 95% CI 1.08-2.73), abnormal symptoms of hyperactivity/inattention (aOR 4.18; 95% CI 3.27-5.34) and modest income (aOR 1.45; 95% CI 1.07-1.96; aOR 1.36; 95% CI 1.01-1.84). Multiple characteristics were associated with elevated levels of symptoms of hyperactivity-inattention and emotional symptoms in children during the period of school closure due to COVID-19. Further studies are needed to help policymakers to balance the pros and cons of closing schools, taking into consideration the educational and psychological consequences for children.

The impact of e-learning during COVID-19 pandemic on students' body aches in Palestine.

Musculoskeletal pain is a major concern in our life due to its negative effects on our ability to perform daily functions. During COVID-19 pandemic, several countries switched their teaching programs into e-learning, where students spend long hour using electronic devices. The use of these devices was associated with several musculoskeletal complains among the students. The aim of this study is to evaluate the different body aches associated with e-learning on university students. The subjects of this study were students from An-Najah University in Palestine. 385 questionnaires were filled using Google forms questionnaire and all the subjects were using e-learning due to COVID-19 pandemic. Our study showed that a large percentage of participants used electronic devices for e-learning during the pandemic. The Duration of these devices use was correlated with duration and degree of pain, and associated with the difficulty in ability to perform several daily activities. Furthermore, most of the students used the sitting position with supine bent forward during the device usage. Thus, the university students that participated in this study had an increase in body aches during the e-learning process, and the aches duration and severity increases if the duration of electronic devices usage increase.

Association of Timing of School Desegregation in the United States With Late-Life Cognition in the Study of Healthy Aging in African Americans (STAR) Cohort.

Importance: Prior research suggests schooling differences for Black individuals in the US are associated with worse cognitive aging. It is unknown whether age when experiencing school desegregation is associated with differences in late-life cognition in this population. Objective: To examine patterns of association between age of school desegregation in grades 1 to 12 and late-life cognition. Design, Setting, and Participants: This cohort study analyzed baseline data from the Study of Healthy Aging in African Americans (STAR) cohort collected from 2018 through 2019 in Northern California, primarily in the cities of Richmond and Oakland. Participants were 699 self-identified Black individuals aged 50 years or older who were community-dwelling, long-term members of Kaiser Permanente Northern California and dementia free at baseline. Exposures: Participants reported whether they attended a segregated school in grades 1, 6, 9, and 12 and were placed in 1 of 6 transition categories: (1) always attended integrated schools; (2) integrated between grades 1 through 5; (3) integrated between grades 6 through 8; (4) integrated between grades 9 through 12; (5) ever moved from integrated to segregated school; (6) never attended integrated schools. Main Outcomes and Measures: Executive function, semantic memory, and verbal episodic memory ascertained via the Spanish and English Neuropsychological Assessment Battery and z standardized for analyses. Results: The mean (SD) age of the 699 participants was 68.5 (8.7) years, and 484 (69.2%) were female. Most participants transitioned from segregated to integrated schools owing to historical timing and cohort geography. Compared with 111 participants who never attended integrated schools (reference group), executive function was better among 50 participants who transitioned to integrated schools between grades 1 and 5 (ß = 0.35; 95% CI, 0.08-0.61; P = .01). Semantic memory was better among 435 participants who only attended integrated schools (ß = 0.34; 95% CI, 0.14-0.54; P = .001) or among 50 participants who transitioned to integrated schools between grades 1 and 5 (ß = 0.43; 95% CI, 0.15-0.72; P = .003). However, no significant differences were found by group for verbal episodic memory function (eg, for 50 participants who transitioned to integrated schools between grades 1 and 5: ß = 0.07; 95% CI, -0.22 to 0.35; P = .66). No significant differences were found when testing for potential interactions by sex, Southern birth, or baseline age. Conclusions and Relevance: The STAR cohort data indicated that executive function and semantic memory were higher among Black individuals with some integrated school experience. These results suggest that racially segregated schooling experiences, including de facto segregation present today, may be associated with worse late-life cognition.

Team Sport Participation Protects Against Burnout During Neurosurgery Training: Cross-Sectional Survey Study.

OBJECTIVE: Burnout is experienced by up to two thirds of neurosurgery residents. Team sport participation as an adolescent protects against adverse mental health outcomes in adulthood. The objective of this study was to determine whether high school or collegiate team sport participation is associated with improved psychological well-being during neurosurgery residency. METHODS: A cross-sectional survey study of U.S. neurosurgery residents was conducted between June 2020 and February 2021. Outcomes included self-ratings of sadness, anxiety, stress, burnout, optimism, and fulfillment, on 100-point scales, which were averaged into a "Burnout Composite Score" (BCS). Respondents were grouped and compared according to their prior self-reported participation in team sports (participants vs. nonparticipants). A 3-way analysis of variance tested the effects of resident level, exercise days, and team sport participation on BCS. RESULTS: Of 229 submitted responses, 228 (99.5%) provided complete data and 185 (81.1%) residents participated in team sports. Days/week of exercise was similar across groups (2.5 ± 1.8 vs. 2.1 ± 1.8, P = 0.20). The team sport group reported lower mean BCS (37.1 vs. 43.6 P = 0.030, Cohen d = 0.369). There was a significant interaction between prior team sport participation and exercise regimen on BCS (F [3, 211] = 3.39, P = 0.019, n2 = 0.046), such that more exercise days per week was associated with decreased BCS for prior team sport athletes (F [3, 211] = 11.10, P < 0.0005), but not for nonparticipants (F [3, 211] = 0.476, P = 0.699). The positive impact of prior team sport participation was more pronounced for senior residents (-11.5 points, P = 0.016) than junior residents (-4.3 points, P = 0.29). CONCLUSIONS: Prior team sport participation was associated with lower BCS among neurosurgery residents, an effect more pronounced during senior residency. Lessons imparted during early team sport experience may have profound impacts on reducing burnout throughout a 7-year neurosurgery residency.

A comparison of child abuse and neglect encounters before and after school closings due to SARS-Cov-2.

BACKGROUND: Risk factors for child abuse and neglect and commonly used reporting mechanisms were highly affected by SARS-Cov-2 pandemic; yet, little is known about the effects of SARS-Cov-2 on rates of child abuse and neglect. OBJECTIVE: To compare overall rates, demographics, types of abuse and acuity of child abuse and neglect encounters seen at one university health system for the 6 months before and after school closings due to the SARS-Cov-2 pandemic. PARTICIPANTS AND SETTING: Data was extracted from a database of billed ICD10 codes for child abuse and neglect including sexual abuse codes. There were 579 encounters for patients <18 years of age and 476 unique patients. METHODS: In addition to ICD10 code and pre/post school closing, each encounter was identified to be inpatient, outpatient and/or emergency department. Demographic data such as age, gender, ethnicity, and race were extracted. Incident rate ratios in addition to descriptive statistics, Mann-Whitney U test, two-sample t-test, or the chi-square test of association were used in the analysis. RESULTS: No significant differences were identified for total rates of child abuse and neglect encounters (p = .08), physical abuse (p = .91) nor child maltreatment (p = .86) codes or in the age (p = .46), gender (p = .58), and race/ethnicity (p = .15) of patient encounters pre- versus post-school closings. The sexual abuse incidence and inpatient encounters increased by 85% (IRR = 1.85, p < .0001; IRR = 1.85, p = .004, respectively). CONCLUSIONS: Our findings provide a unique contribution to the existing literature in that we identified a significant increase in the incidence of sexual abuse and higher patient acuity as evidenced by higher rates of inpatient encounters after school closing due to SARS-Cov-2.

Acute Subdural Hematoma in High School Rugby Players in Japan: The Importance of Playing Experience for Injury Prevention.

OBJECTIVES: Acute subdural hematoma (ASDH) is known to be devasting sport-related head injury but it is relatively rare in rugby compared with other contact sports. Certain cases of ASDH have happened in high school rugby players in Japan. To prevent them from the injury we report a background of the players. METHODS: Data of high school rugby players who suffered ASDH were extracted from injury reports in the Japan Rugby Football Union between April 2004 and March 2020. The number of injured players, diagnosis on the report, school year, phase of play where the injury occurred, and playing career were analyzed. RESULTS: There were 30 cases of ASDH including 16 cases in the first year, 9 in the second year, and 5 in the third year of playing. Phase of play was mainly being tackled in 11 (37%), and tackling in 13 (43%). Novice players, defined as a player having less playing experience of rugby during junior high school, accounted for 77% of phase of tackling, 82% of being tackled. First year novice players accounted for 100% of phase of being tackled. Outcome within 6 months after injury was recovery in 14, morbidity in 6, mortality in 2, and unknown in 8. CONCLUSIONS: Playing experience in high school rugby players should be considered as an important factor for prevention of ASDH-in particular, phase of being tackled is riskier than that of tackling for first year novice players.

The impact of school reopening on the spread of COVID-19 in England.

By mid-May 2020, cases of COVID-19 in the UK had been declining for over a month; a multi-phase emergence from lockdown was planned, including a scheduled partial reopening of schools on 1 June 2020. Although evidence suggests that children generally display mild symptoms, the size of the school-age population means the total impact of reopening schools is unclear. Here, we present work from mid-May 2020 that focused on the imminent opening of schools and consider what these results imply for future policy. We compared eight strategies for reopening primary and secondary schools in England. Modifying a transmission model fitted to UK SARS-CoV-2 data, we assessed how reopening schools affects contact patterns, anticipated secondary infections and the relative change in the reproduction number, R. We determined the associated public health impact and its sensitivity to changes in social distancing within the wider community. We predicted that reopening schools with half-sized classes or focused on younger children was unlikely to push R above one. Older children generally have more social contacts, so reopening secondary schools results in more cases than reopening primary schools, while reopening both could have pushed R above one in some regions. Reductions in community social distancing were found to outweigh and exacerbate any impacts of reopening. In particular, opening schools when the reproduction number R is already above one generates the largest increase in cases. Our work indicates that while any school reopening will result in increased mixing and infection amongst children and the wider population, reopening schools alone in June 2020 was unlikely to push R above one. Ultimately, reopening decisions are a difficult trade-off between epidemiological consequences and the emotional, educational and developmental needs of children. Into the future, there are difficult questions about what controls can be instigated such that schools can remain open if cases increase. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.

Shut and re-open: the role of schools in the spread of COVID-19 in Europe.

We investigate the effect of school closure and subsequent reopening on the transmission of COVID-19, by considering Denmark, Norway, Sweden and German states as case studies. By comparing the growth rates in daily hospitalizations or confirmed cases under different interventions, we provide evidence that school closures contribute to a reduction in the growth rate approximately 7 days after implementation. Limited school attendance, such as older students sitting exams or the partial return of younger year groups, does not appear to significantly affect community transmission. In countries where community transmission is generally low, such as Denmark or Norway, a large-scale reopening of schools while controlling or suppressing the epidemic appears feasible. However, school reopening can contribute to statistically significant increases in the growth rate in countries like Germany, where community transmission is relatively high. In all regions, a combination of low classroom occupancy and robust test-and-trace measures were in place. Our findings underscore the need for a cautious evaluation of reopening strategies. This article is part of the theme issue 'Modelling that shaped the early COVID-19 pandemic response in the UK'.

School-aged neurodevelopmental outcomes for children born extremely preterm.

As survival rates for children born extremely preterm (EP, <28 weeks' gestation) have increased with advances in perinatal and neonatal care, their long-term functioning and quality of life assume more importance. Outcomes in early childhood provide some information, but outcomes at school-age are more informative of life-long functioning. Children born EP at school-age have substantially higher rates of intellectual impairment, poorer executive, academic and motor function, more neurodevelopmental disability, and poorer health-related quality of life than do contemporaneous term-born controls. Because the rates of adverse outcomes remain unacceptably high, and particularly since some outcomes may be deteriorating rather than improving over time, new strategies to ameliorate these problems, targeting periods before, during and after birth, and throughout the lifespan, are a priority.

SARS-CoV-2 transmission in students of public schools of Catalonia (Spain) after a month of reopening.

INTRODUCTION: SARS-CoV-2 transmission within schools and its contribution to community transmission are still a matter of debate. METHODS: A retrospective cohort study in all public schools in Catalonia was conducted using publicly available data assessing the association between the number of reported SARS-CoV-2 cases among students and staff in weeks 1-2 (Sept 14-27th, 2020) of the academic year with school SARS-CoV-2 incidence among students in weeks 4-5. A multilevel Poisson regression model adjusted for the community incidence in the corresponding basic health area (BHA) and the type of school (primary or secondary), with random effects at the sanitary region and BHA levels, was performed. RESULTS: A total of 2184 public schools opened on September 14th with 778,715 students. Multivariate analysis showed a significant association between the total number of SARS-CoV-2 cases in a centre in weeks 1-2 and the SARS-CoV-2 school incidence among students in weeks 4-5 (Risk Ratio (RR) 1.074, 95% CI 1.044-1.105, p-value <0.001). The adjusted BHA incidence in the first two weeks was associated with school incidence in weeks 4-5 (RR 1.002, 95% CI 1.002-1.003, p-value <0.001). Secondary schools showed an increased incidence in weeks 4 and 5 (RR primary vs secondary 1.709 95% CI 1.599-1.897, p-value <0.001). CONCLUSIONS: Safety measures adopted by schools were not enough to stop related-to-school transmission in students and could be improved. The safest way to keep schools open is to reduce community transmission down to a minimum.

Simulation-based evaluation of school reopening strategies during COVID-19: A case study of São Paulo, Brazil.

During the coronavirus disease 2019 (COVID-19) pandemic, many countries opted for strict public health measures, including closing schools. After some time, they have started relaxing some of those restrictions. To avoid overwhelming health systems, predictions for the number of new COVID-19 cases need to be considered when choosing a school reopening strategy. Using a computer simulation based on a stochastic compartmental model that includes a heterogeneous and dynamic network, we analyse different strategies to reopen schools in the São Paulo Metropolitan Area, including one similar to the official reopening plan. Our model allows us to describe different types of relations between people, each type with a different infectiousness. Based on our simulations and model assumptions, our results indicate that reopening schools with all students at once has a big impact on the number of new COVID-19 cases, which could cause a collapse of the health system. On the other hand, our results also show that a controlled school reopening could possibly avoid the collapse of the health system, depending on how people follow sanitary measures. We estimate that postponing the schools' return date for after a vaccine becomes available may save tens of thousands of lives just in the São Paulo Metropolitan Area compared to a controlled reopening considering a worst-case scenario. We also discuss our model constraints and the uncertainty of its parameters.

Modeling the interplay between demography, social contact patterns, and SARS-CoV-2 transmission in the South West Shewa Zone of Oromia Region, Ethiopia.

BACKGROUND: COVID-19 spread may have a dramatic impact in countries with vulnerable economies and limited availability of, and access to, healthcare resources and infrastructures. However, in sub-Saharan Africa, a low prevalence and mortality have been observed so far. METHODS: We collected data on individuals' social contacts in the South West Shewa Zone (SWSZ) of Ethiopia across geographical contexts characterized by heterogeneous population density, work and travel opportunities, and access to primary care. We assessed how socio-demographic factors and observed mixing patterns can influence the COVID-19 disease burden, by simulating SARS-CoV-2 transmission in remote settlements, rural villages, and urban neighborhoods, under school closure mandate. RESULTS: From national surveillance data, we estimated a net reproduction number of 1.62 (95% CI 1.55-1.70). We found that, at the end of an epidemic mitigated by school closure alone, 10-15% of the population residing in the SWSZ would have been symptomatic and 0.3-0.4% of the population would require mechanical ventilation and/or possibly result in a fatal outcome. Higher infection attack rates are expected in more urbanized areas, but the highest incidence of critical disease is expected in remote subsistence farming settlements. School closure contributed to reduce the reproduction number by 49% and the attack rate of infections by 28-34%. CONCLUSIONS: Our results suggest that the relatively low burden of COVID-19 in Ethiopia observed so far may depend on social mixing patterns, underlying demography, and the enacted school closures. Our findings highlight that socio-demographic factors can also determine marked heterogeneities across different geographical contexts within the same region, and they contribute to understand why sub-Saharan Africa is experiencing a relatively lower attack rate of severe cases compared to high-income countries.