scholarly journals Assessing Age-Specific Vaccination Strategies and Post-Vaccination Reopening Policies for COVID-19 Control Using SEIR Modeling Approach

2021 ◽  
Author(s):  
Xia Wang ◽  
Hulin Wu ◽  
Sanyi Tang
Keyword(s):  
Age Structure ◽  
Age Groups ◽  
Social Contact ◽  
The Elderly ◽  
Vaccination Rate ◽  
Social Contacts ◽  
Post Vaccination ◽  
Vaccination Strategies ◽  
Contact Patterns ◽  
Effect Of Age

AbstractBackgroundAs the availability of COVID-19 vaccines, it is badly needed to develop vaccination guidelines to prioritize the vaccination delivery in order to effectively stop COVID-19 epidemic and minimize the loss.MethodsWe evaluated the effect of age-specific vaccination strategies on the number of infections and deaths using an SEIR model, considering the age structure and social contact patterns for different age groups for each of different countries.ResultsIn general, the vaccination priority should be given to those younger people who are active in social contacts to minimize the number of infections; while the vaccination priority should be given to the elderly to minimize the number of deaths. But this principle may not always apply when the interaction of age structure and age-specific social contact patterns is complicated. Partially reopening schools, workplaces or households, the vaccination priority may need to be adjusted accordingly.ConclusionsPrematurely reopening social contacts could initiate a new outbreak or even a new pandemic out of control if the vaccination rate and the detection rate are not high enough. Our result suggests that it requires at least nine months of vaccination before fully reopening social contacts in order to avoid a new pandemic.

scholarly journals Vaccination strategies for minimizing loss of life in Covid-19 in a Europe lacking vaccines

2021 ◽  
Author(s):  
Patrick Hunziker
Keyword(s):  
European Union ◽  
Age Groups ◽  
Vaccine Dose ◽  
Vaccination Strategy ◽  
The Elderly ◽  
The European Union ◽  
Social Contacts ◽  
Loss Of Life ◽  
Vaccination Strategies ◽  
Reduced Dose

AbstractAim and BackgroundWe aimed at identifying vaccination strategies that minimize loss of life in the Covid-19 pandemic. Covid-19 mainly kills the elderly, but the pandemic is driven by social contacts that are more frequent in the young. Vaccines elicit stronger immune responses per dose in younger persons. As vaccine production is a bottleneck, many countries have adopted a strategy of first vaccinating the elderly and vulnerable, while postponing vaccination of the young.MethodsBased on published age-stratified immunogenicity data of the Moderna mRNA-1273 vaccine, we compared the established “one dose fits all” approach with tailored strategies: The known differential immunogenicity of vaccine doses in different age groups is exploited to vaccinate the elderly at full dose, while the young receive a reduced dose, amplifying the number of individuals receiving the vaccine early. A modeling approach at European Union scale with population structure, Covid-19 case and death rates similar to Europe in late January 2021 is used.ResultsWhen the elderly were vaccinated preferentially, the pandemic initially continued essentially unchecked, as it was dominantly driven by social contacts in other age groups. Tailored strategies, including regular dosing in the elderly but reduced dose vaccination in the young, multiplied early vaccination counts, and even with some loss in protection degree for the individual person, the protective effect towards stopping the pandemic and protecting lives was enhanced, even for the elderly. In the European Union, pandemic duration (threshold >100’000 cases/day) was shortened from 53 to 18-24 days; cumulative death count over 100 days was reduced by >30’000. Data suggest that the findings may be relevant to both, the Moderna and the Pfizer-BioNTech mRNA vaccines.ConclusionProtecting the vulnerable, minimizing overall deaths and stopping the pandemic is best achieved by an adaptive vaccination strategy using an age-tailored vaccine dose, in this model parameterized to European demographics, coronavirus transmission observations and vaccine characteristics.

scholarly journals The differential impact of physical distancing strategies on social contacts relevant for the spread of COVID-19: Evidence from a multi-country survey

2020 ◽  
Author(s):  
Emanuele Del Fava ◽  
Jorge Cimentada ◽  
Daniela Perrotta ◽  
André Grow ◽  
Francesco Rampazzo ◽  
...  
Keyword(s):  
Disease Transmission ◽  
Age Groups ◽  
Social Contact ◽  
The United States ◽  
Social Contacts ◽  
Contact Patterns ◽  
The Uk ◽  
Facebook Advertising ◽  
Net Reproduction ◽  
The Impact

AbstractPhysical distancing measures are intended to mitigate the spread of COVID-19, even though their impact on social contacts and disease transmission remains unclear. Obtaining timely data on social contact patterns can help to assess the impact of such protective measures. We conducted an online opt-in survey based on targeted Facebook advertising campaigns across seven European countries (Belgium, France, Germany, Italy, Netherlands, Spain, United Kingdom (UK)) and the United States (US), achieving a sample of 53,708 questionnaires in the period March 13–April 13, 2020. Post-stratification weights were produced to correct for biases. Data on social contact numbers, as well as on protective behaviour and perceived level of threat were collected and used to the expected net reproduction number by week, Rt, with respect to pre-pandemic data. Compared to social contacts reported prior to COVID-19, in mid-April daily social contact numbers had decreased between 49% in Germany and 83% in Italy, ranging from below three contacts per day in France, Spain, and the UK up to four in Germany and the Netherlands. Such reductions were sufficient to bring Rt to one or even below in all countries, except Germany. Evidence from the US and the UK showed that the number of daily social contacts mainly decreased after governments issued the first physical distancing guidelines. Finally, although contact numbers decreased uniformly across age groups, older adults reported the lowest numbers of contacts, indicating higher levels of protection. We provided a comparable set of statistics on social contact patterns during the COVID-19 pandemic for eight high-income countries, disaggregated by week. As these estimates offer a more grounded alternative to the theoretical assumptions often used in epidemiological models, the scientific community could draw on this information for developing more realistic epidemic models of COVID-19.

scholarly journals The demographic dividend is more than an education dividend

2020 ◽  
Vol 117 (42) ◽  
pp. 25982-25984
Author(s):  
Rainer Kotschy ◽  
Patricio Suarez Urtaza ◽  
Uwe Sunde
Keyword(s):  
Human Capital ◽  
Age Structure ◽  
Age Distribution ◽  
Age Groups ◽  
Demographic Dividend ◽  
Positive Growth ◽  
Working Age ◽  
Age Structured ◽  
Positive Effect ◽  
Effect Of Age

The demographic dividend has long been viewed as an important factor for economic development and provided a rationale for policies aiming at a more balanced age structure through birth control and family planning. Assessing the relative importance of age structure and increases in human capital, recent work has argued that the demographic dividend is related to education and has suggested a dominance of improving education over age structure. Here we reconsider the empirical relevance of shifts in the age distribution for development for a panel of 159 countries over the period 1950 to 2015. Based on a flexible model of age-structured human capital endowments, the results document important interactions between age structure and human capital endowments, suggesting that arguments of clear dominance of education over age structure are unwarranted and lead to potentially misleading policy conclusions. An increase in the working-age population share has a strong and significant positive effect on growth, even conditional on human capital, in line with the conventional notion of a demographic dividend. An increase in human capital only has positive growth effects if combined with a suitable age structure. An increasing share of the most productive age groups has an additional positive effect on economic performance. Finally, the results show considerable heterogeneity in the effect of age structure and human capital for different levels of development. Successful policies for sustainable development should take this heterogeneity into account to avoid detrimental implications of a unidimensional focus on human capital without accounting for demography.

The effect of age, environment and management on social contact patterns in sheep

2020 ◽  
Vol 225 ◽  
pp. 104964
Author(s):  
Laura Ozella ◽  
Joss Langford ◽  
Laetitia Gauvin ◽  
Emily Price ◽  
Ciro Cattuto ◽  
...  
Keyword(s):  
Social Contact ◽  
Contact Patterns ◽  
Effect Of Age

scholarly journals Using wearable proximity sensors to characterize social contact patterns in a village of rural Malawi

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Laura Ozella ◽  
Daniela Paolotti ◽  
Guilherme Lichand ◽  
Jorge P. Rodríguez ◽  
Simon Haenni ◽  
...  
Keyword(s):  
High Resolution ◽  
Social Dynamics ◽  
Social Protection ◽  
Social Contact ◽  
Early Morning ◽  
Clear Trend ◽  
Social Contacts ◽  
Middle Income ◽  
Contact Patterns ◽  
The Village

AbstractMeasuring close proximity interactions between individuals can provide key information on social contacts in human communities and related behaviours. This is even more essential in rural settings in low- and middle-income countries where there is a need to understand contact patterns for the implementation of strategies for social protection interventions. We report the quantitative assessment of contact patterns in a village in rural Malawi, based on proximity sensors technology that allows for high-resolution measurements of social contacts. Our results revealed that the community structure of the village was highly correlated with the household membership of the individuals, thus confirming the importance of the family ties within the village. Social contacts within households occurred mainly between adults and children, and adults and adolescents and most of the inter-household social relationships occurred among adults and among adolescents. At the individual level, age and gender social assortment were observed in the inter-household network, and age disassortativity was instead observed in intra-household networks. Moreover, we obtained a clear trend of the daily contact activity of the village. Family members congregated in the early morning, during lunch time and dinner time. In contrast, inter-household contact activity displayed a growth from the morning, reaching a maximum in the afternoon.The proximity sensors technology used in this study provided high resolution temporal data characterized by timescales comparable with those intrinsic to social dynamics and it thus allowed to have access to the level of information needed to understand the social context of the village.

scholarly journals COVID-19 mortality across selected states in India: the role of age structure.

2021 ◽  
Author(s):  
Mohamed Jainul Azarudeen ◽  
Tanzin Dikid ◽  
Karishma Kurup ◽  
Khyati Aroskar ◽  
Himanshu Chauhan ◽  
...  
Keyword(s):  
Mortality Rate ◽  
Age Structure ◽  
Disease Surveillance ◽  
Economic Status ◽  
Age Groups ◽  
The Elderly ◽  
Mortality Rates ◽  
Health System Intervention ◽  
Indirect Standardization ◽  
Standardized Mortality Rate

Background Mortality rates provide an opportunity to identify and act on the health system intervention for preventing deaths. Hence, it is essential to appreciate the influence of age structure while reporting mortality for a better summary of the magnitude of the epidemic. Objectives We described and compared the pattern of COVID-19 mortality standardized by age between selected states and India from January to November 2020. Methods We initially estimated the Indian population for 2020 using the decadal growth rate from the previous census (2011). This was followed by estimations of crude and age-adjusted mortality rate per million for India and the selected states. We used this information to perform indirect standardization and derive the age-standardized mortality rates for the states for comparison. In addition, we derived a ratio for age-standardized mortality to compare across age groups within the state. We extracted information regarding COVID-19 deaths from the Integrated Disease Surveillance Programme special surveillance portal up to November 16, 2020. Results The crude mortality rate of India stands at 88.9 per million population(118,883/1,337,328,910). Age-adjusted mortality rate (per million) was highest for Delhi (300.5) and lowest for Kerala (35.9).The age-standardized mortality rate (per million) for India is (<15 years=1.6, 15-29 years=6.3, 30-44 years=35.9, 45-59 years=198.8, 60-74 years=571.2, & ≥75 years=931.6). The ratios for age-standardized mortality increase proportionately from 45-59 years age group across all the states. Conclusion There is high COVID-19 mortality not only among the elderly ages, but we also identified heavy impact of COVID-19 on the working population. Therefore, we recommend further evaluation of age-adjusted mortality for all States and inclusion of variables like gender, socio-economic status for standardization while identifying at-risk populations and implementing priority public health actions. Keywords COVID-19, Mortality, Age Standardized Mortality Rate, Indirect Standardization.

scholarly journals Estimating data-driven COVID-19 mitigation strategies for safe university reopening

2021 ◽  
Author(s):  
Qihui Yang ◽  
Don M. Gruenbacher ◽  
Caterina M. Scoglio
Keyword(s):  
Extreme Events ◽  
Social Contact ◽  
The United States ◽  
Vaccination Rate ◽  
Mitigation Strategies ◽  
Contact Patterns ◽  
University Population ◽  
The University ◽  
University Settings ◽  
Pharmaceutical Interventions

AbstractAfter one pandemic year of remote or hybrid instructional modes, universities in the United States are now planning for an in-person fall semester in 2021. However, it is uncertain what the vaccination rate will look like after students, faculty, and staff return to campus. To help inform university-reopening policies, we collected survey data on social contact patterns and developed an agent-based model to simulate the spread of COVID-19 in university settings. In this paper, we aim to identify the immunity threshold that, if exceeded, would lead to a relatively safe on-campus experience for the university population. With relaxed non-pharmaceutical interventions, we estimated that immunity in at least 60% of the university population is needed for safe university reopening. Still, attention needs to be paid to extreme events that could lead to huge infection size spikes. At an immune level of 60%, continuing non-pharmaceutical interventions, such as wearing masks, could lead to an 89% reduction in the maximum cumulative infection, which reflects the possible non-negligible infection size from extreme events.

scholarly journals Age-related changes in plasma lycopene concentrations, but not in vitamin E, are associated with fat mass

2000 ◽  
Vol 84 (5) ◽  
pp. 711-716 ◽  
Author(s):  
Pascal Grolier ◽  
Yves Boirie ◽  
Evelyne Levadoux ◽  
Marion Brandolini ◽  
Patrick Borel ◽  
...  
Keyword(s):  
Vitamin E ◽  
Fat Mass ◽  
Plasma Cholesterol ◽  
Age Groups ◽  
The Elderly ◽  
Fat Free Mass ◽  
Plasma Vitamin ◽  
Tocopherol Concentration ◽  
Age Related ◽  
Effect Of Age

The aim of the present study was to assess the influence of age on plasma concentration of α-tocopherol, retinol and carotenoids with a special attention paid to natural differences in body composition. Forty healthy subjects were recruited: twenty were less than 35 years old and twenty above 60 years old. Males and females were equally represented in each age group. Subjects were kept in energy balance and received controlled diets for 36 h. Fat mass and fat-free mass were determined with the180-enriched water dilution technique. Plasma vitamins A and E, and carotenoid levels were determined after 12 h fasting and were shown to be similar in women and men. Plasma α-tocopherol concentration increased with age (+44 % elderlyv.young), and correlated with % fat mass and plasma cholesterol. After adjustment for plasma cholesterol, the effect of age and % fat mass disappeared. In contrast, plasma lycopene level was 2-fold lower in the elderly than in the young group, and was inversely correlated with fat mass. When lycopene values were adjusted for fat mass, the effect of age disappeared. These results suggest that plasma levels of vitamin E and lycopene differed in the two age groups and that differences in plasma cholesterol and fat mass might participate in such an effect. Short-term vitamin intake did not appear to influence plasma vitamin concentrations.

Social contact patterns and leprosy disease: a case-control study in Bangladesh

2012 ◽  
Vol 141 (3) ◽  
pp. 573-581 ◽  
Author(s):  
S. G. FEENSTRA ◽  
Q. NAHAR ◽  
D. PAHAN ◽  
L. OSKAM ◽  
J. H. RICHARDUS
Keyword(s):  
Case Control Study ◽  
Important Determinant ◽  
Social Contact ◽  
Risk Groups ◽  
Case Control ◽  
Control Measures ◽  
Social Contacts ◽  
Contact Patterns ◽  
Endemic Areas ◽  
Control Study

SUMMARYSocioeconomic and culturally defined social contact patterns are expected to be an important determinant in the continuing transmission of Mycobacterium leprae in leprosy-endemic areas. In a case-control study in two districts in Bangladesh, we assessed the association between social contact patterns and the risk of acquiring clinical leprosy. Social contacts of 90 recently diagnosed patients were compared to those of 199 controls. Leprosy was associated with a more intensive social contact pattern in the home [odds ratio (OR) 1·09, 95% confidence interval (CI) 1·00–1·19, P = 0·043] and in the nearby neighbourhood (OR 1·07, 95% CI 1·03–1·11, P = 0·001). Although it is known that M. leprae spreads most easily within households of infected persons, in endemic areas social contacts within the neighbourhood, village or urban ward, also appear to be important for transmission. We advise that disease control measures in leprosy-endemic areas should not be limited to households, but include high-risk groups in the nearby neighbourhood of patients.

Spatial diversity of demographic aging in Poland

2016 ◽  
Vol 61 (2) ◽  
pp. 62-72
Author(s):  
Małgorzata Podogrodzka
Keyword(s):  
Age Structure ◽  
Age Groups ◽  
The Elderly ◽  
Spatial Diversity ◽  
Explanatory Variables ◽  
Younger Age ◽  
Demographic Aging ◽  
The Relationship ◽  
Test Objects ◽  
Two Age Groups

In the assessment of the demographic age and ageing a lot of measures are being exploited. Among the most commonly used may be mentioned those which express the relationship between the number of people in two age groups (the elderly and the general population or younger age group). Rarely are used such measures, which take into account all the age structure of the population. The article presents a new method to analyze spatial diversity of the population age structure using the method of agglomeration with the Euclidean metric. The test objects were the voivodships (provinces), and the explanatory variables were five-year age groups (20 variables). In addition, a hypothetical business was introduced, which has a regressive age structure. Its introduction allowed for an evaluation of how the test regions differ not only among themselves, but also how far they deviate from the pattern of development of the Polish population. Considerations were conducted separately for men and women and the 1991, 2001, 2011.

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