Vaccination Strategy for the COVID-19 Pandemic in Early 2021 Based on Differences in People's Behavior Between Tokyo and Osaka, Japan

2021 ◽  
Author(s):  
Hidenori Yasuda ◽  
Fuyu ITO ◽  
Ken-ichi HANAKI ◽  
Kazuo SUZUKI
Keyword(s):  
High Risk ◽  
Reproduction Number ◽  
Vaccination Strategy ◽  
Infected People ◽  
Mathematical Simulations ◽  
Osaka Prefecture ◽  
Western Japan ◽  
Fourth Wave ◽  
Eastern Japan ◽  
Active Generation

Abstract Background: During the fourth COVID-19 wave in Japan, a marked difference was apparent in the scale of the epidemic between Metropolitan Tokyo in eastern Japan and Osaka prefecture in western Japan.Methods: Public epidemic data were analyzed, with performance of mathematical simulations using simplified SEIR models.Results: The increase in the number of infected persons per 100,000 population during the fourth wave of expansion was greater in Osaka than in Tokyo. The basic reproduction number in Osaka was greater than in Tokyo. Particularly, the number of infected people in their 20s increased during the fourth wave: the generation-specific reproduction number of people in their 20s was higher than people of other generations. Both Tokyo and Osaka had strong correlation between the increase in the number of infected people and the average number of people using the main downtown stations at night. Simulations showed vaccination of people in their 60s and older reduced the number of infected people among the high-risk elderly population in the fourth wave. However, age-specific vaccination of people in their 20s reduced the number of infected people more than vaccination of people in their 60s and older.Conclusions: Differences in the epidemic between Tokyo and Osaka are explainable by different behaviors of the most socially active generation. When vaccine supplies are adequate, priority should be assigned to high-risk older adults, but if vaccine supplies are scarce, simulation results suggest consideration of vaccinating specific groups among whom the epidemic is spreading rapidly.

Evolution of Sex Chromosome Heteromorphy in Geographic Populations of the Japanese Tago’s Brown Frog Complex

2021 ◽  
pp. 1-9
Author(s):  
Chiao Kuwana ◽  
Hiroyuki Fujita ◽  
Masataka Tagami ◽  
Takanori Matsuo ◽  
Ikuo Miura
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Mitochondrial Gene ◽  
Population Level ◽  
Chromosome 7 ◽  
Geographic Population ◽  
Geographic Populations ◽  
Western Japan ◽  
Brown Frog ◽  
Eastern Japan

The sex chromosomes of most anuran amphibians are characterized by homomorphy in both sexes, and evolution to heteromorphy rarely occurs at the species or geographic population level. Here, we report sex chromosome heteromorphy in geographic populations of the Japanese Tago’s brown frog complex (2n = 26), comprising Rana sakuraii and R. tagoi. The sex chromosomes of R. sakuraii from the populations in western Japan were homomorphic in both sexes, whereas chromosome 7 from the populations in eastern Japan were heteromorphic in males. Chromosome 7 of R. tagoi, which is distributed close to R. sakuraii in eastern Japan, was highly similar in morphology to the Y chromosome of R. sakuraii. Based on this and on mitochondrial gene sequence analysis, we hypothesize that in the R. sakuraii populations from eastern Japan the XY heteromorphic sex chromosome system was established by the introduction of chromosome 7 from R. tagoi via interspecies hybridization. In contrast, chromosome 13 of R. tagoi from the 2 large islands in western Japan, Shikoku and Kyushu, showed a heteromorphic pattern of constitutive heterochromatin distribution in males, while this pattern was homomorphic in females. Our study reveals that sex chromosome heteromorphy evolved independently at the geographic lineage level in this species complex.

scholarly journals Rotavirus Vaccination of Infants Delayed and Limited within the National Immunization Programme in the Netherlands: An Opportunity Lost

Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 144
Author(s):  
Florian Zeevat ◽  
Evgeni Dvortsin ◽  
Abrham Wondimu ◽  
Jan C. Wilschut ◽  
Cornelis Boersma ◽  
...  
Keyword(s):  
High Risk ◽  
The Netherlands ◽  
Herd Immunity ◽  
Vaccination Strategy ◽  
Quality Adjusted Life Year ◽  
High Risk Group ◽  
Universal Vaccination ◽  
Birth Cohorts ◽  
Rotavirus Vaccination ◽  
Immunization Programme

In this study, we estimated the benefits of rotavirus vaccination for infants had the rotavirus vaccine been introduced in the Netherlands as of its market authorization in 2006. An age-structured, deterministic cohort model was developed to simulate different birth cohorts over a period of 15 years from 2006 until 2021, comparing both universal and targeted high-risk group vaccination to no vaccination. Different scenarios for the duration of protection (5 or 7 years) and herd immunity (only for universal vaccination) were analyzed. All birth cohorts together included 2.6 million infants, of which 7.9% were high-risk individuals, and an additional 13.2 million children between 1–15 years born prior to the first cohort in 2006. The costs and health outcomes associated with rotavirus vaccination were calculated per model scenario and discounted at 4% and 1.5%, respectively. Our analysis reveals that, had rotavirus vaccination been implemented in 2006, it would have prevented 356,800 (51% decrease) and 32,200 (5% decrease) cases of rotavirus gastroenteritis after universal and targeted vaccination, respectively. Over the last 15 years, this would have led to significant avoided costs and quality-adjusted life year losses for either vaccination strategy with the most favorable outcomes for universal vaccination. Clearly, an opportunity has been lost.

scholarly journals Impact of early detection and vaccination strategy in COVID-19 eradication program in Jakarta, Indonesia

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Dipo Aldila ◽  
Brenda M. Samiadji ◽  
Gracia M. Simorangkir ◽  
Sarbaz H. A. Khosnaw ◽  
Muhammad Shahzad
Keyword(s):  
Mathematical Model ◽  
Basic Reproduction Number ◽  
Reproduction Number ◽  
Vaccination Strategy ◽  
Vaccination Rate ◽  
Rapid Testing ◽  
Social Distancing ◽  
Rapid Spread ◽  
Vaccine Potential ◽  
The Basic Reproduction Number

Abstract Objective Several essential factors have played a crucial role in the spreading mechanism of COVID-19 (Coronavirus disease 2019) in the human population. These factors include undetected cases, asymptomatic cases, and several non-pharmaceutical interventions. Because of the rapid spread of COVID-19 worldwide, understanding the significance of these factors is crucial in determining whether COVID-19 will be eradicated or persist in the population. Hence, in this study, we establish a new mathematical model to predict the spread of COVID-19 considering mentioned factors. Results Infection detection and vaccination have the potential to eradicate COVID-19 from Jakarta. From the sensitivity analysis, we find that rapid testing is crucial in reducing the basic reproduction number when COVID-19 is endemic in the population rather than contact trace. Furthermore, our results indicate that a vaccination strategy has the potential to relax social distancing rules, while maintaining the basic reproduction number at the minimum possible, and also eradicate COVID-19 from the population with a higher vaccination rate. In conclusion, our model proposed a mathematical model that can be used by Jakarta’s government to relax social distancing policy by relying on future COVID-19 vaccine potential.

scholarly journals Assessing Interventions against Coronavirus Disease 2019 (COVID-19) in Osaka, Japan: A Modeling Study

2021 ◽  
Vol 10 (6) ◽  
pp. 1256
Author(s):  
Ko Nakajo ◽  
Hiroshi Nishiura
Keyword(s):  
Model Comparison ◽  
Reproduction Number ◽  
State Of Emergency ◽  
Illness Onset ◽  
Epidemic Dynamics ◽  
Osaka Prefecture ◽  
Time Of Infection ◽  
Single Intervention ◽  
Second Wave ◽  
Combined Interventions

Estimation of the effective reproduction number, R(t), of coronavirus disease (COVID-19) in real-time is a continuing challenge. R(t) reflects the epidemic dynamics based on readily available illness onset data, and is useful for the planning and implementation of public health and social measures. In the present study, we proposed a method for computing the R(t) of COVID-19, and applied this method to the epidemic in Osaka prefecture from February to September 2020. We estimated R(t) as a function of the time of infection using the date of illness onset. The epidemic in Osaka came under control around 2 April during the first wave, and 26 July during the second wave. R(t) did not decline drastically following any single intervention. However, when multiple interventions were combined, the relative reductions in R(t) during the first and second waves were 70% and 51%, respectively. Although the second wave was brought under control without declaring a state of emergency, our model comparison indicated that relying on a single intervention would not be sufficient to reduce R(t) < 1. The outcome of the COVID-19 pandemic continues to rely on political leadership to swiftly design and implement combined interventions capable of broadly and appropriately reducing contacts.

scholarly journals Impact of national influenza vaccination strategy in severe influenza outcomes among the high-risk Portuguese population

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ausenda Machado ◽  
Irina Kislaya ◽  
Amparo Larrauri ◽  
Carlos Matias Dias ◽  
Baltazar Nunes
Keyword(s):  
High Risk ◽  
Influenza Vaccination ◽  
Seasonal Influenza ◽  
Vaccine Coverage ◽  
Vaccination Strategy ◽  
High Risk Population ◽  
Risk Population ◽  
Seasonal Influenza Vaccination ◽  
Severe Influenza ◽  
The Impact

Abstract Background All aged individuals with a chronic condition and those with 65 and more years are at increased risk of severe influenza post-infection complications. There is limited research on cases averted by the yearly vaccination programs in high-risk individuals. The objective was to estimate the impact of trivalent seasonal influenza vaccination on averted hospitalizations and death among the high-risk population in Portugal. Methods The impact of trivalent seasonal influenza vaccination was estimated using vaccine coverage, vaccine effectiveness and the number of influenza-related hospitalizations and deaths. The number of averted events (NAE), prevented fraction (PF) and number needed to vaccinate (NVN) were estimated for seasons 2014/15 to 2016/17. Results The vaccination strategy averted on average approximately 1833 hospitalizations and 383 deaths per season. Highest NAE was observed in the ≥65 years population (85% of hospitalizations and 95% deaths) and in the 2016/17 season (1957 hospitalizations and 439 deaths). On average, seasonal vaccination prevented 21% of hospitalizations in the population aged 65 and more, and 18.5% in the population with chronic conditions. The vaccination also prevented 29% and 19.5% of deaths in each group of the high-risk population. It would be needed to vaccinate 3360 high-risk individuals, to prevent one hospitalization and 60,471 high-risk individuals to prevent one death. Conclusion The yearly influenza vaccination campaigns had a sustained positive benefit for the high-risk population, reducing hospitalizations and deaths. These results can support public health plans toward increased vaccine coverage in high-risk groups.

A multigroup model for cholera dynamics and control

2015 ◽  
Vol 09 (01) ◽  
pp. 1650001 ◽  
Author(s):  
Drew Posny ◽  
Chairat Modnak ◽  
Jin Wang
Keyword(s):  
Reproduction Number ◽  
Vaccination Strategy ◽  
Sharp Threshold ◽  
Indirect Transmission ◽  
Dynamics And Control ◽  
Simulation Results ◽  
Transmission Pathways ◽  
And Control ◽  
Control Study ◽  
The Basic Reproduction Number

We propose a general multigroup model for cholera dynamics that involves both direct and indirect transmission pathways and that incorporates spatial heterogeneity. Under biologically feasible conditions, we show that the basic reproduction number R0 remains a sharp threshold for cholera dynamics in multigroup settings. We verify the analysis by numerical simulation results. We also perform an optimal control study to explore optimal vaccination strategy for cholera outbreaks.

scholarly journals A fractional order mathematical model for COVID-19 dynamics with quarantine, isolation, and environmental viral load

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohammed A. Aba Oud ◽  
Aatif Ali ◽  
Hussam Alrabaiah ◽  
Saif Ullah ◽  
Muhammad Altaf Khan ◽  
...  
Keyword(s):  
Epidemic Model ◽  
Reproduction Number ◽  
Model Parameters ◽  
Disease Dynamics ◽  
Threshold Parameter ◽  
Fractional Model ◽  
Infected People ◽  
Fractional Models ◽  
Disease Epidemics ◽  
The Impact

AbstractCOVID-19 or coronavirus is a newly emerged infectious disease that started in Wuhan, China, in December 2019 and spread worldwide very quickly. Although the recovery rate is greater than the death rate, the COVID-19 infection is becoming very harmful for the human community and causing financial loses to their economy. No proper vaccine for this infection has been introduced in the market in order to treat the infected people. Various approaches have been implemented recently to study the dynamics of this novel infection. Mathematical models are one of the effective tools in this regard to understand the transmission patterns of COVID-19. In the present paper, we formulate a fractional epidemic model in the Caputo sense with the consideration of quarantine, isolation, and environmental impacts to examine the dynamics of the COVID-19 outbreak. The fractional models are quite useful for understanding better the disease epidemics as well as capture the memory and nonlocality effects. First, we construct the model in ordinary differential equations and further consider the Caputo operator to formulate its fractional derivative. We present some of the necessary mathematical analysis for the fractional model. Furthermore, the model is fitted to the reported cases in Pakistan, one of the epicenters of COVID-19 in Asia. The estimated value of the important threshold parameter of the model, known as the basic reproduction number, is evaluated theoretically and numerically. Based on the real fitted parameters, we obtained $\mathcal{R}_{0} \approx 1.50$ R 0 ≈ 1.50 . Finally, an efficient numerical scheme of Adams–Moulton type is used in order to simulate the fractional model. The impact of some of the key model parameters on the disease dynamics and its elimination are shown graphically for various values of noninteger order of the Caputo derivative. We conclude that the use of fractional epidemic model provides a better understanding and biologically more insights about the disease dynamics.

scholarly journals Genetic characteristics of Apodemus speciosus at Akiyoshidai Quasi-National Park in Yamaguchi Prefecture

2021 ◽  
Author(s):  
Hiroyuki Imai ◽  
Hiroshi Tanaka ◽  
Taiki Matsuo ◽  
Seto Miho ◽  
Sumito Matsuya ◽  
...  
Keyword(s):  
National Park ◽  
Radiation Effects ◽  
Continuous Monitoring ◽  
Small Rodent ◽  
Apodemus Speciosus ◽  
Genetic Characteristics ◽  
Model Animal ◽  
Western Japan ◽  
Eastern Japan ◽  
Type Chromosome

The large Japanese field mouse (Apodemus speciosus) is a small rodent endemic to Japan. The mice have a genetic characteristic in which the number of chromosomes differs between those from western Japan and those from eastern Japan. A. spesiosus, found throughout Japan, is used as a model animal for geogenetics and monitoring of radiation effects of wildlife. In this present study, to elucidate the genetic characteristics of the mice Akiyoshidai Quasi-National Park in Yamaguchi Prefecture, we investigated mitochondrial DNA and chromosome numbers. As a result, A. speciosus from Yamaguchi Prefecture were classified into the Honshu-Shikoku-Kyushu group and had a western Japan-type chromosome set of 2n=46; however, some Yamaguchi Prefecture mice formed a genetic cluster in Yamaguchi Prefecture, suggesting that continuous monitoring is needed to reveal the dynamics of genetic diversity.

Information technologies for collecting and processing material on clinical course of HIV infection in epidemiological assessment of risks of contact infection in foci of combined pathology. HIV infection and tuberculosis

2021 ◽  
pp. 47-50
Author(s):  
N. V. Lukyanenko ◽  
N. Ya. Lukyanenko ◽  
V. V. Shevchenko ◽  
M. A. Asmanova
Keyword(s):  
High Risk ◽  
Hiv Infection ◽  
Clinical Studies ◽  
Information Technologies ◽  
Clinical Course ◽  
Epidemiological Surveillance ◽  
Clinical Aspects ◽  
Infected People ◽  
Processing Material ◽  
Incidence Increase

Due to the incidence increase of tuberculosis, there is increasing need for epidemiological surveillance of concomitant pathologies among HIV-infected people. The main goal of the authors is to develop information technologies for collecting and processing material on the incidence of HIV infection and tuberculosis in assessing the risks of contamination of contacts in the foci and the effectiveness of epidemiological response. There are descriptive and evaluative epidemiological research methods, the results of clinical studies at the work. There are also presented the features of clinical aspects of concomitant pathology that affect the risk of developing tuberculosis in contact persons. The work presents optimization of use of databases and standard computer programs, which will make it possible to carry out a comprehensive epidemiological assessment of the risks of contamination of contacts in foci of HIV infection and tuberculosis, to determine belonging of the outbreak to groups of high risk of developing tuberculosis in contact, to determine a wider range of contacts and the boundaries of the outbreak.

scholarly journals Incorporating Rapid HIV Testing into Partner Counseling and Referral Services

2008 ◽  
Vol 123 (3_suppl) ◽  
pp. 126-135 ◽  
Author(s):  
Elin B. Begley ◽  
Alexandra M. Oster ◽  
Binwei Song ◽  
Linda Lesondak ◽  
Kelly Voorhees ◽  
...  
Keyword(s):  
High Risk ◽  
Hiv Infection ◽  
Hiv Testing ◽  
The United States ◽  
High Risk Population ◽  
Newly Diagnosed ◽  
Infected People ◽  
Rapid Hiv Testing ◽  
Undiagnosed Hiv ◽  
Locating Information

Objectives. Partner counseling and referral services (PCRS) provide a unique opportunity to decrease transmission of human immunodeficiency virus (HIV) by notifying sex and drug-injection partners of HIV-infected individuals of their exposure to HIV. We incorporated rapid HIV testing into PCRS to reduce barriers associated with conventional HIV testing and identify undiagnosed HIV infection within this high-risk population. Methods. From April 2004 through June 2006, HIV-infected people (index clients) were interviewed, and their partners were notified of their potential exposure to HIV and offered rapid HIV testing at six sites in the United States. The numbers of index clients participating and the numbers of partners interviewed and tested were compared by site. Descriptive and bivariate analyses were performed. Results. A total of 2,678 index clients were identified, of whom 779 (29%) provided partner locating information. A total of 1,048 partners were elicited, of whom 463 (44%) were both interviewed and tested for HIV. Thirty-seven partners (8%) were newly diagnosed with HIV. The number of index clients interviewed to identify one partner with newly diagnosed HIV infection ranged from 10 to 137 at the participating sites. Conclusions. PCRS provides testing and prevention services to people at high risk for HIV infection. Incorporating rapid HIV testing into PCRS and identifying previously undiagnosed infections likely confer individual and public health benefits. Further evaluation is needed to determine the best methods of identifying partners with previously unrecognized HIV infection.

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