scholarly journals COVID-19 Vaccine Prioritisation in Japan and South Korea

2021 ◽  
Author(s):  
June Young Chun ◽  
Hwichang Jeong ◽  
Philippe Beutels ◽  
Norio Ohmagari ◽  
Yongdai Kim ◽  
...  
Keyword(s):  
South Korea ◽  
Vaccine Efficacy ◽  
Optimal Allocation ◽  
Case Reports ◽  
Vaccination Strategy ◽  
Sensitivity Analyses ◽  
Allocation Strategy ◽  
Death Toll ◽  
Specific Contact ◽  
Bayesian Inference Method

Background Due to a limited initial supply of COVID-19 vaccines, the prioritisation of individuals for vaccination is of utmost importance for public health. Here, we provide the optimal allocation strategy for COVID-19 vaccines according to age in Japan and South Korea. Methods Combining national case reports, age-specific contact matrices, and observed periods between each stages of infection (Susceptible-Exposed-Infectious-Quarantined), we constructed a compartmental model. We estimated the age-stratified probability of transmission given contact (q_i) using Bayesian inference method and simulated different vaccination scenarios to reduce either case numbers or death toll. We also performed sensitivity analyses on the proportion of asymptomatic cases and vaccine efficacy. Findings The model inferred age-stratified probability of transmission given contact (q_i) showed similar age-dependent increase in Japan and South Korea. Assuming the reported COVID-19 vaccine efficacy, our results indicate that Japan and South Korea need to prioritise individuals aged 20-35 years and individuals aged over 60 years, respectively, to minimise case numbers. To minimise the death toll, both countries need to prioritise individuals aged over 75 years. These trends were not changed by proportions of asymptomatic cases and varying vaccine efficacy on individuals under 20 years. Interpretation We presented the optimal vaccination strategy for Japan and South Korea. Comparing the results of these countries demonstrates that not only the effective contact rates containing q_i but also the age-demographics of current epidemic in Japan (dominance in 20s) and South Korea (dominant cases over 50s) affect vaccine allocation strategy.

scholarly journals Optimal Allocation of the Limited COVID-19 Vaccine Supply in South Korea

2021 ◽  
Vol 10 (4) ◽  
pp. 591
Author(s):  
Eunha Shim
Keyword(s):  
South Korea ◽  
Vaccine Efficacy ◽  
Optimal Allocation ◽  
Age Distribution ◽  
Case Fatality ◽  
Vaccination Strategy ◽  
Years Of Life Lost ◽  
Incidence And Mortality ◽  
Specific Contact ◽  
Epidemiological Characteristics

Initial supply of the coronavirus disease (COVID-19) vaccine may be limited, necessitating its effective use. Herein, an age-structured model of COVID-19 spread in South Korea is parameterized to understand the epidemiological characteristics of COVID-19. The model determines optimal vaccine allocation for minimizing infections, deaths, and years of life lost while accounting for population factors, such as country-specific age distribution and contact structure, and various levels of vaccine efficacy. A transmission-blocking vaccine should be prioritized in adults aged 20–49 years and those older than 50 years to minimize the cumulative incidence and mortality, respectively. A strategy to minimize years of life lost involves the vaccination of adults aged 40–69 years, reflecting the relatively high case-fatality rates and years of life lost in this age group. An incidence-minimizing vaccination strategy is highly sensitive to vaccine efficacy, and vaccines with lower efficacy should be administered to teenagers and adults aged 50–59 years. Consideration of age-specific contact rates and vaccine efficacy is critical to optimize vaccine allocation. New recommendations for COVID-19 vaccines under consideration by the Korean Centers for Disease Control and Prevention are mainly based on a mortality-minimizing allocation strategy.

scholarly journals Vaccine Effects on Susceptibility and Symptomatology Can Change the Optimal Allocation of COVID-19 Vaccines: South Korea as an Example

2021 ◽  
Vol 10 (13) ◽  
pp. 2813
Author(s):  
Wongyeong Choi ◽  
Eunha Shim
Keyword(s):  
South Korea ◽  
Optimal Allocation ◽  
Age Groups ◽  
Vaccination Strategy ◽  
Epidemiological Data ◽  
Health Interventions ◽  
Risk Of Disease ◽  
Age Structured ◽  
Effective Public Health ◽  
Country Specific

The approved coronavirus disease (COVID-19) vaccines reduce the risk of disease by 70–95%; however, their efficacy in preventing COVID-19 is unclear. Moreover, the limited vaccine supply raises questions on how they can be used effectively. To examine the optimal allocation of COVID-19 vaccines in South Korea, we constructed an age-structured mathematical model, calibrated using country-specific demographic and epidemiological data. The optimal control problem was formulated with the aim of finding time-dependent age-specific optimal vaccination strategies to minimize costs related to COVID-19 infections and vaccination, considering a limited vaccine supply and various vaccine effects on susceptibility and symptomatology. Our results suggest that “susceptibility-reducing” vaccines should be relatively evenly distributed among all age groups, resulting in more than 40% of eligible age groups being vaccinated. In contrast, “symptom-reducing” vaccines should be administered mainly to individuals aged 20–29 and ≥60 years. Thus, our study suggests that the vaccine profile should determine the optimal vaccination strategy. Our findings highlight the importance of understanding vaccine’s effects on susceptibility and symptomatology for effective public health interventions.

scholarly journals An analysis of the potential global impact of dosing regimen and rollout options for the ChAdOx1 nCoV-19 vaccine

2021 ◽  
Author(s):  
Ricardo Aguas ◽  
Anouska Bharath ◽  
Lisa White ◽  
Bo Gao ◽  
Merryn Voysey ◽  
...  
Keyword(s):  
High Risk ◽  
Low Income ◽  
Vaccine Efficacy ◽  
Socioeconomic Development ◽  
Optimal Allocation ◽  
Vaccination Strategy ◽  
Risk Groups ◽  
High Risk Group ◽  
Low Income Countries ◽  
Time Interval

Abstract Background The ongoing COVID-19 pandemic has placed an unprecedented health and economic burden on countries at all levels of socioeconomic development, emphasizing the need to evaluate the most effective vaccination strategy in multiple, diverse environments. The high reported efficacy, low cost, and long shelf-life of the ChAdOx1 nCoV-19 vaccine positions it well for evaluation in different settings. Methods Using data from the ongoing ChAdOx1 nCoV-19 clinical trials, an individual-based model was constructed to predict the 6-month population-level impact of vaccine deployment. A detailed probabilistic sensitivity analysis (PSA) was developed to evaluate the importance of epidemiological, demographic, immunological, and logistical factors in determining vaccine effectiveness. Using representative countries, logistical plans for vaccination rollout at various levels of vaccine availability and delivery speed, conditional on vaccine efficacy profiles (efficacy of the booster dose, time interval between doses, and relative efficacy of the first dose) were explored.Findings and Interpretation Our results highlight how expedient vaccine delivery to high-risk groups is critical in mitigating COVID-19 disease and mortality. In scenarios where the number of vaccine doses available is insufficient for high-risk groups (those aged more than 65 years) to receive two vaccine doses, administration of a single dose of vaccine is optimal. This effect is consistent even when vaccine efficacy after one dose is just 75% of the levels achieved after two doses. These findings offer a nuanced perspective of the critical drivers of COVID-19 vaccination effectiveness and can inform optimal allocation strategies. These are relevant to high-income countries with a large high-risk group population as well as to low-income countries with younger populations, where the cost and logistical challenges of procuring and delivering two doses for each citizen represent a significant challenge.

scholarly journals Public health impact of delaying second dose of BNT162b2 or mRNA-1273 covid-19 vaccine: simulation agent based modeling study

BMJ ◽  
2021 ◽  
pp. n1087
Author(s):  
Santiago Romero-Brufau ◽  
Ayush Chopra ◽  
Alex J Ryu ◽  
Esma Gel ◽  
Ramesh Raskar ◽  
...  
Keyword(s):  
Hospital Admissions ◽  
Vaccination Strategy ◽  
Population Based ◽  
Agent Based Modeling ◽  
Sensitivity Analyses ◽  
Agent Based ◽  
Cumulative Mortality ◽  
Vaccination Rates ◽  
Dose Strategy ◽  
Modeling Study

AbstractObjectiveTo estimate population health outcomes with delayed second dose versus standard schedule of SARS-CoV-2 mRNA vaccination.DesignSimulation agent based modeling study.SettingSimulated population based on real world US county.ParticipantsThe simulation included 100 000 agents, with a representative distribution of demographics and occupations. Networks of contacts were established to simulate potentially infectious interactions though occupation, household, and random interactions.InterventionsSimulation of standard covid-19 vaccination versus delayed second dose vaccination prioritizing the first dose. The simulation runs were replicated 10 times. Sensitivity analyses included first dose vaccine efficacy of 50%, 60%, 70%, 80%, and 90% after day 12 post-vaccination; vaccination rate of 0.1%, 0.3%, and 1% of population per day; assuming the vaccine prevents only symptoms but not asymptomatic spread (that is, non-sterilizing vaccine); and an alternative vaccination strategy that implements delayed second dose for people under 65 years of age, but not until all those above this age have been vaccinated.Main outcome measuresCumulative covid-19 mortality, cumulative SARS-CoV-2 infections, and cumulative hospital admissions due to covid-19 over 180 days.ResultsOver all simulation replications, the median cumulative mortality per 100 000 for standard dosing versus delayed second dose was 226 v 179, 233 v 207, and 235 v 236 for 90%, 80%, and 70% first dose efficacy, respectively. The delayed second dose strategy was optimal for vaccine efficacies at or above 80% and vaccination rates at or below 0.3% of the population per day, under both sterilizing and non-sterilizing vaccine assumptions, resulting in absolute cumulative mortality reductions between 26 and 47 per 100 000. The delayed second dose strategy for people under 65 performed consistently well under all vaccination rates tested.ConclusionsA delayed second dose vaccination strategy, at least for people aged under 65, could result in reduced cumulative mortality under certain conditions.

scholarly journals The Public Health Impact of Delaying a Second Dose of the BNT162b2 or mRNA-1273 COVID-19 Vaccine

2021 ◽  
Author(s):  
Santiago Romero-Brufau ◽  
Ayush Chopra ◽  
Alex J Ryu ◽  
Esma Gel ◽  
Ramesh Raskar ◽  
...  
Keyword(s):  
Vaccination Strategy ◽  
Population Level ◽  
Health Impact ◽  
Vaccination Rate ◽  
Agent Based Modeling ◽  
Sensitivity Analyses ◽  
Agent Based ◽  
Cumulative Mortality ◽  
Vaccination Rates ◽  
The Public

AbstractObjectivesTo estimate population health outcomes under delayedsecond dose versus standard schedule SARS-CoV-2 mRNA vaccination.DesignAgent-based modeling on a simulated population of 100,000 based on a real-world US county. The simulation runs were replicated 10 times. To test the robustness of these findings, simulations were performed under different estimates for single-dose efficacy and vaccine administration rates, and under the possibility that a vaccine prevents only symptoms but not asymptomatic spread.Settingpopulation level simulation.Participants100,000 agents are included in the simulation, with a representative distribution of demographics and occupations. Networks of contacts are established to simulate potentially infectious interactions though occupation, household, and random interactionsInterventionswe simulate standard Covid-19 vaccination, versus delayed-second-dose vaccination prioritizing first dose. Sensitivity analyses include first-dose vaccine efficacy of 70%, 80% and 90% after day 12 post-vaccination; vaccination rate of 0.1%, 0.3%, and 1% of population per day; assuming the vaccine prevents only symptoms but not asymptomatic spread; and an alternative vaccination strategy that implements delayed-second-dose only for those under 65 years of age.Main outcome measurescumulative Covid-19 mortality over 180 days, cumulative infections and hospitalizations.ResultsOver all simulation replications, the median cumulative mortality per 100,000 for standard versus delayed second dose was 226 vs 179; 233 vs 207; and 235 vs 236; for 90%, 80% and 70% first-dose efficacy, respectively. The delayed-second-dose strategy was optimal for vaccine efficacies at or above 80%, and vaccination rates at or below 0.3% population per day, both under sterilizing and non-sterilizing vaccine assumptions, resulting in absolute cumulative mortality reductions between 26 and 47 per 100,000. The delayed-second-dose for those under 65 performed consistently well under all vaccination rates tested.ConclusionsA delayed-second-dose vaccination strategy, at least for those under 65, could result in reduced cumulative mortality under certain conditions.

scholarly journals A Statistical Modeling of the Course of COVID-19 (SARS-CoV-2) Outbreak: A Comparative Analysis

2020 ◽  
Vol 32 (4) ◽  
pp. 157-160 ◽  
Author(s):  
Handan Ankarali ◽  
Seyit Ankarali ◽  
Hulya Caskurlu ◽  
Yasemin Cag ◽  
Ferhat Arslan ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Severe Acute Respiratory Syndrome ◽  
South Korea ◽  
Statistical Modeling ◽  
Model Prediction ◽  
Genetic Differences ◽  
The Other ◽  
Death Toll ◽  
Natural Logarithm ◽  
Cubic Model

This study aims to provide both a model by using cumulative cases and cumulative death toll for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) outbreak in four countries, China, Italy, South Korea, and Turkey, starting from the first diagnosis and to compare associated indicators. The most successful estimation was obtained from the cubic model with natural logarithm for China, Italy, South Korea, and Turkey. The success of the models was around 99%. However, differences began to emerge in China, Italy, and South Korea after the second week. Although the highest number of new cases per 1 million people in China was 9.8 on February 28, 2020; it was 108.4 on March 21, 2020, in Italy; and this was 16.6 on March 5, 2020, in South Korea. On the other hand, the number of new cases was 24.6 per 1 million people on March 27, 2020, in Turkey. The log-cubic model proposed in this study has been set forth to obtain successful results for aforementioned countries, as well as to estimate the course of the COVID-19 outbreak. Other factors such as climacteric factors and genetic differences, which may have an impact on viral spreading and transmission, would also have strengthened the model prediction capacity.

Multi-objective optimal allocation strategy for the energy internet in Huangpu District, Guangzhou, China

2020 ◽  
Vol 14 (2) ◽  
pp. 241-253
Author(s):  
Pei Li ◽  
Guotian Cai ◽  
Yuntao Zhang ◽  
Shangjun Ke ◽  
Peng Wang ◽  
...  
Keyword(s):  
Optimal Allocation ◽  
Allocation Strategy ◽  
Energy Internet ◽  
Multi Objective

scholarly journals Some Notes on the Formation of a Pair in Pairs Trading

Mathematics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 348 ◽  
Author(s):  
José Pedro Ramos-Requena ◽  
Juan Evangelista Trinidad-Segovia ◽  
Miguel Ángel Sánchez-Granero
Keyword(s):  
Hurst Exponent ◽  
Optimal Allocation ◽  
Mean Reversion ◽  
Equal Weight ◽  
Allocation Strategy ◽  
Pairs Trading ◽  
Distance Correlation ◽  
Statistical Arbitrage ◽  
New Methodologies ◽  
Set Up

The main goal of the paper is to introduce different models to calculate the amount of money that must be allocated to each stock in a statistical arbitrage technique known as pairs trading. The traditional allocation strategy is based on an equal weight methodology. However, we will show how, with an optimal allocation, the performance of pairs trading increases significantly. Four methodologies are proposed to set up the optimal allocation. These methodologies are based on distance, correlation, cointegration and Hurst exponent (mean reversion). It is showed that the new methodologies provide an improvement in the obtained results with respect to an equal weighted strategy.

Continued Root-End Growth and Apexification Using a Calcium Hydroxide and Iodoform Paste (Metapex®): Three Case Reports

2010 ◽  
Vol 11 (5) ◽  
pp. 63-70 ◽  
Author(s):  
Shobha Tandon ◽  
N. Sridhar
Keyword(s):  
South Korea ◽  
Root Growth ◽  
Calcium Hydroxide ◽  
Clinical Significance ◽  
Case Reports ◽  
Endodontic Treatment ◽  
Permanent Teeth ◽  
Root Canals ◽  
Disposable Plastic ◽  
Clinical Cases

Abstract Aim The aim of these case reports is to present a treatment to promote root-end growth and apexification in nonvital immature permanent teeth in children. Methods and Materials Three cases were presented where the calcium hydroxide and iodoform paste Metapex® was placed in the root canals of immature permanent teeth using disposable plastic tips. The teeth involved were evaluated radiographically at regular intervals for the first 12 months after placement of the paste. At the end of 12 months all the cases showed continued root growth and apical closure (apexification) with no evidence of periapical pathology. Conventional endodontic treatment was then performed. Results In all three of the clinical cases presented, a combination of calcium hydroxide and iodoform paste (Metapex®) was used and showed promising results in inducing root-end growth and closure after 12 months. Conclusion In these three clinical cases, the calcium hydroxide and iodoform paste Metapex® (Meta Biomed Co. Ltd., South Korea) was found to induce apical closure when assessed radiographically. Over a period of 12 months all the cases showed continued root growth. Clinical Significance The calcium hydroxide and iodoform paste Metapex® promoted continued root-end growth with apexification in the nonvital immature permanent teeth treated. Citation Sridhar N, Tandon S. Continued Root-Growth and Apexification Using a Calcium Hydroxide and Iodoform Paste (Metapex®): Three Case Reports. J Contemp Dent Pract [Internet]. 2010 October; 11(5):063-070. Available from: http://www.thejcdp.com/journal/view/volume11- issue5-sridhar

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