Numerical Simulation of the COVID-19 Herd Immunity Based on Complex Network Modeling

Constructing an epidemic dynamic model and exploring the spreading law of epidemic have very important theoretical significance for epidemic prevention and control. Based on the existing homogeneous mixing model, in view of the increasingly obvious heterogeneity of individual contact relationships, and each individual is in a different contact relationship, a dynamic small-world network model that takes into account individual status. Contact tracking has been established to simulate the spread of the COVID-19 in society. By comparing the simulation results, the rationality of the built model is explained. On this basis, the simulation calculated the impact of the network topology and the proportion of vaccinated people on the spread of the COVID-19, analyzed the critical value of herd immunity. The established propagation model is reasonable, and feasible to achieve herd immunization by vaccination. © 2023 Editorial Borad of Complex Systems and Complexity Science. All rights reserved.

Healthcare costs vis-à-vis economic growth in pandemic crisis with technology adoption

COVID-19 pandemic brought up issues with healthcare costs, national economic development and welfare of the society in forefront. Nations across the globe followed different approaches to deal with COVID-19, such as zero tolerance, herd immunity, containment to build treatment capability. National healthcare became a contentious sociopolitical issue involving healthcare costs, technologies and societal health. In the United States even during the COVID-19 pandemic, the government approach was pursuing a sustainable improvement in patient care through adoption of medical and information technologies. The national healthcare policies are framed around technological interventions with the assumption that deployment of technologies could keep healthcare costs under control and at the same time improve health outcomes. However, evidences show that the healthcare costs are in the rise even with impressive progress in technological deployment. This article highlights some of the recent trends in healthcare costs, technological preparedness, medical technology developments in managing COVID-19 pandemic. The US government mandated electronic health record (EHR) systems implementation and assess its impact on healthcare costs and health outcomes. This article emphasizes the need for understanding the interconnectedness of costs, technology and societal health.

Health Economic Evaluation of COVID-19 Vaccines: A Systematic Literature Review

Objectives: The COVID19 pandemic caused over six million deaths worldwide as of 2022 and made necessary the rapid development of vaccines. The objective of this Systematic Literature Review is to summarise the main evidence from economic evaluations of vaccines against COVID19. Method(s): Searches were conducted on PubMed on July 13th 2022. The selected papers considered COVID19 vaccination scenarios without population limits. The types of study design examined were cost-benefit and cost-effectiveness analyses. Result(s): Overall, 16 articles from an initial list of 1842 were included in this review. Out of the 16 models, there were five Markov cohort models (three of them were combined with a decision tree model), four dynamic transmission models, three microsimulation models, three epidemiological models (without further information on the model structure) and one decision tree model. Model characteristics were considerably consistent between high-, middle- or low-income countries. Five studies considered both the healthcare and societal perspective, while seven studies reported only the former, and one only the latter. Two studied did not specify the study perspective. Ten of the studies did not consider any level of herd immunity, and no study considered cross-protection. Although eight studies used "naive" comparisons between vaccines, none of the studies conducted thorough indirect treatment comparison. All the models suggest that vaccines are cost-effective as they prevent death and transmission, and reduce the severity of cases. Although the sources of effectiveness estimates were always stated, the details of those studies were rarely reported. Nevertheless, the outcome measures and the key parameters used in the models were generally clearly stated and justified. Conclusion(s): This SLR highlights several challenges for conducting Health Economic evaluations of COVID19 vaccines. The quality of the models and their estimates suffered from the very fast pace of COVID19 research. Therefore, economic evidence on vaccination programs requires additional rigorous research.Copyright © 2023

Vaccination Identification System using Raspberry Pi

The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) causes Covid-19, an infectious illness. A methodology was created to track the vaccination history of people with the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) that causes Covid-19, an infectious illness. The system operates on a Raspberry Pi processor that is designed to authenticate the vaccination records of individuals. The Vaccination Identification System consists of various components connected to the Raspberry Pi Zero 2W microprocessor, Pi camera, an LCD display, LED indicators, a buzzer, a DC servo motor, and a PCB converter. The proposed system grants access to vaccinated individuals and denies access to those who are not vaccinated.

The impact of vaccination on the dynamics of the Omicron variant of SARS-CoV-2

In the context of vaccination, we develop a novel mathematical model to examine the Omicron type of coronavirus illness. The system's mathematical analysis based on its equilibrium points shall be obtained. The threshold quantity is used to investigate the system's local and global asymptotical analysis. The Omicron vaccination model shown to be stable locally asymptotically if R 0 v < 1 . The system is globally asymptotically stable at the disease-free equilibrium for a special case when η = 1 if R 0 v < 1 . We estimate the model parameters based on the observed data and show that the threshold is R 0 ≈ 2.4894 in the absence of vaccination. The model has the phenomenon of backward bifurcation under certain conditions. Herd immunity analysis is obtained and it turns out that the herd immunity threshold for the South African population is 74%. The impact of vaccination on disease dynamics is also shown and discussed. Further, we have given some graphical results showing the community's disease reduction. [ FROM AUTHOR] Copyright of Waves in Random & Complex Media is the property of Taylor & Francis Ltd and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)

Herd culture and herd immunity

Although communicable diseases affect our bodies, they occur in a society that interprets and gives them meaning. Herd immunity provides the body protection;however, long-term protection requires shifts in the way people interpret and respond to disease, cultural transformation that enables the development of the knowledge, habits and skills that make herd immunity feasible and sustainable. Herd culture allows individuals to protect themselves and restrict their liberty in order to protect others;it is a form of exercising positive liberty and a necessary complement to herd immunity in a democratic society. Key words Herd immunity, Herd culture, COVID-19, Liberty, Cultural changeAlternate :Resumen Aunque las enfermedades transmisibles afectan nuestros cuerpos, ocurren en una sociedad que las interpreta y dota de significado, y cuyos individuos causan o evitan. La inmunidad de rebaño permite lograr una protección del cuerpo, sin embargo, para su sustentabilidad, se requiere de cambios en la manera cómo las personas interpretan y responden a la enfermedad, de transformaciones culturales que permitan desarrollar conocimientos, hábitos y destrezas que hagan factible y sostenible la inmunidad de rebaño. La cultura de rebaño permite a los individuos protegerse y restringir su libertad para proteger a los demás, es una forma de ejercicio de la libertad positiva y el complemento necesario de la inmunidad del rebaño en la sociedad democrática.Palabras clave:Inmunidad de rebaño;Cultura de rebaño;COVID-19;Libertad;Cambios culturales

England's health policy response to covid-19

Government prioritised the NHS but was slow to protect social care

Frontiers of COVID-19: Scientific and Clinical Aspects of the Novel Coronavirus 2019

This book aims to serve the critical interests of the global community by supplying the most current knowledge and understanding of Covid-19 epidemiology, treatment, and prognoses. There was much uncertain and contradictory information published in the first year of the novel coronavirus. The dynamics of COVID-19 have now been realized, including the type of antibodies produced in infected patients and their limited lasting endurance. This book will set the record straight on the concept of "herd immunity” and explore the current vaccine trials taking place in different countries. This comprehensive book will illuminate recent advances regarding COVID-19 and offer a possible roadmap on how to move forward. Frontiers of COVID-19: A Pathophysiology and Epidemiology Roadmap of Novel Coronavirus Disease will be a vital and forward-looking guide for infectious disease clinicians, scientists and researchers, and students at the graduate level. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.

The Failure to Establish Herd Immunity Against SARSCoV-2

The current COVID-19 pandemic is undoubtedly one of the most severe global healthcare crises in the 21st century. The traditional view on terminating a pandemic is establishing herd immunity via natural infections or vaccinations. However, this strategy might not be appropriate against SARS-CoV-2 due to many uncontrollable factors. This review has summarised several newest primary research and clinical studies to evaluate the reasons behind the failure of establishing this indirect protection with some alternative insights regarding future disease control. The review has found that variables such as the duration of humoral immunity against SARS-CoV-2, vaccines' ability to cut off the transmission, and the continuous emergence of immune evasive variants are vital contributors to the failed herd immunity establishment. Therefore, the overdependence on vaccination during the pandemic will not only waste valuable time and resources on disease containment but also creates this false illusion which dampens the public's alertness to the disease and amplifies the pandemic's impacts on world healthcare systems and economics. As a result, the traditional disease control policies, such as lockdown and quarantines, are as vital as vaccination for future infectious disease containment and pandemic management. It is the combination of both strategies that contribute to the establishment of herd immunity and pandemic termination. © 2023 SPIE.

Comparison of Achievements in the Implementation of COVID-19 Vaccination in Five Provinces to Establish Herd Immunity in Indonesia in the Perspective of the New Public Service.

This study aims to analyze the achievements of coronavirus disease-2019 (COVID-19) vaccination in five provinces in Indonesia, North Maluku, West Sulawesi, Maluku, West Papua, and Papua. Furthermore, to establish herd immunity in the new normal perspective. Vaccination is important because it is an effective way to build immunity. This method uses qualitative research with a Qualitative Data Analysis Software (QDAS) approach. The source of data was obtained from the official website of the government, the ministry of health, in the category of areas with low vaccination achievement, and data were also obtained by capturing news in credible official media to find the cause of the low vaccination rate in the community. The data analyst uses NVivo12 software to code and visualizes data in graphs, images, and word clouds. The findings of this study indicate that in five provinces in Indonesia, North Maluku (68%), West Sulawesi (76%), Maluku (66%), West Papua (62%), and Papua (41%), the achievement of vaccination implementation is still relatively low. Due to doubts in the community about the status of the vaccine, information and communication education from the government have not been optimal; the environment and geography vary, so it becomes an obstacle in carrying out vaccination.

Health belief and behaviour: an analysis of the predictors for receiving COVID-19 vaccines in Malaysia

PurposeThe paper examines the ‘Intention to Receive the COVID-19 Vaccines' or IRV from three perspectives: the health belief model, behavioural economics, and institutional quality.Design/methodology/approachThis study provides quantitative analysis by applying Chi-squared test of contingencies, paired sample t-tests, exploratory factor analysis, and multiple linear regression (stepwise method) on the data collected from 591 respondents mainly from Malaysia.FindingsThe results show that Perceived Benefits, Perceived Barriers, Perceived Susceptibility, Herding, and Institutional Quality play roles as predictors of IRV. Perceived Benefits play the most crucial role among the predictors and Perceived Barriers is the least important predictor. People have the herding mentality after being exposed to information encouraging such behaviour.Originality/valueThis study reveals that the respondents changed their behaviour in different circumstances when exposed to information that incorporates the effect of herding. Herding mentality, the effectiveness of government authorities, and regulatory quality have become important factors in enriching public health policies and the effectiveness of interventions.

The Changing Impact of Vaccines in the Covid-19 Pandemic: A Modeling Study

Background: Much of the world's population had already been infected with COVID-19 by the time that the Omicron variant emerged at the end of 2021, but the scale of the Omicron wave was larger than any that had come before or since, and left a global imprinting of immunity which changed the COVID landscape. In this study, we explore the changing value of vaccines in a landscape of dynamic immunity and rapidly evolving variants of concern. Method(s): We use Covasim, an established agent-based model of COVID-19 enhanced with detailed intra-host dynamics. First, we simulate a vaccine trial over March 2020 - April 2022 within a population resembling that of South Africa, and estimate how both vaccine efficacy (reduction in the risk of severe disease for vaccinated vs unvaccinated individuals) and efficiency (number of doses needed to avert a death) change as the population experiences waves of wild-type, Beta, Delta, and Omicron infections. Next, we introduce six hypothetical variants starting from February 2022 and evaluate the impact of (a) the existing set of vaccines, and (b) vaccines specifically targeted to the new variants. Result(s): We estimate that within our simulated population, vaccine efficacy against severe disease decreased from 80% to 20% in the wake of the first wave of wild-type COVID-19, then increased back to ~70% over the latter half of 2020 as population immunity waned. This pattern repeated following each subsequent wave of infections, with vaccine efficacy falling to its lowest (10%) in the immediate wake of the Omicron wave in December 2021. The efficiency of vaccination decreases over time at an increasing rate: at peak efficiency, fewer than 100 doses would have been required to avert a single death, but by the end of January 2022, we estimate that nearly 4,000 doses would be required to avert a single death. We find that variant-chasing vaccines will only add value above pre-existing vaccines if we can shorten the window between variant introduction and vaccine deployment to under three weeks, an impossible time-frame without significant NPI use. Conclusion(s): Although the vaccines have proven to be remarkably effective, our work demonstrates that the population immunity acquired over the first two years of the pandemic significantly reduced the impact per dose of doses delivered after this time. Next-generation vaccines to fight future COVID variants and/or other respiratory diseases must be delivered rapidly at scale for vaccine strategies to be maximally effective.

SARS-CoV-2 COLLECTIVE IMMUNITY AMONG THE POPULATION OF THE REPUBLIC OF ARMENIA

Background. The COVID-19 pandemic has become a substantial global health crisis, unparalleled in world history. Infection dynamics can have specific characteristics in different countries due to social, economic, climatic, or geographic factors. Aim(s): to study features of SARS-CoV-2 collective immunity among the Armenian population. Materials and methods. A cross-sectional, randomized study of collective immunity was carried out according to a program developed by Rospotrebnadzor and the St. Petersburg Pasteur Institute, taking into account WHO recommendations. The study was approved by the ethics committees of the National Center for Infectious Diseases (Armenia) and the St. Petersburg Pasteur Institute (Russia). A volunteer cohort was formed (N = 6057), randomized by age and region. The study's analysis included: shares and distributions of antibodies (Abs) to nucleocapsid (Nc) antigen (Ag) and receptor binding domain (RBD) S-1 Ag in the cohort;and quantitative determination of these Abs by ELISA. During the survey, a history of vaccination was indicated by 4395 people. Results. Overall seropositivity formed in the whole cohort (by April 14, 2022) was 98.6% (95% CI: 98.1-98.7). It did not depend on age, place of residence, or occupation. When quantifying Nc and RBD Abs, the proportions of volunteers with Nc Ab levels of 1-17 BAU/ml and RBD Ab levels of 22.6-220 BAU/ml were the smallest, amounting to 6.9% (95% CI: 6.2-7.5) and 20.4% (95% CI: 19.4-21.4), respectively. With increasing serum concentrations (Nc > 667 BAU/ml, RBD > 450 BAU/ml), the proportions of individuals with the corresponding levels were 20.2% for Nc (95% CI: 19.2-21.3) and 54.2% for RBD (95% CI: 52.9-55.5). Vaccination coverage was 72.6% (95% CI: 71.5-73.7). The most frequently used were Sinopharm/BIBP (32.4%), AZD1222 (22.3%), and Gam-COVID-Vac (21%). The remaining vaccines (CoronaVac, mRNA-1273, BNT162b2, CoviVac) were used by 24.3% of vaccinated individuals. When summing vaccines by platform, it was found that: vector vaccines were used in 40.34% (95% CI: 33.57-42.39) of cases;whole-virion vaccines were used in 26.83% (95% CI: 24.76-32.20);and mRNA vaccines were used in 6.33% (95% CI: 4.84-8.91). Conclusion. The epidemic situation in Armenia by April 2022 was characterized by a high level of collective immunity, independent of age or regional factors. Vector and whole-virion vaccines have been used most widely.Copyright © Popova A.Yu. et al., 2023.

COVID-19 vaccine acceptance in pregnant women of block Hazratbal, Kashmir

Background: Coronavirus disease 2019 (COVID-19) is a disease caused by a novel coronavirus (2019-nCoV) that was first reported in Wuhan, Hubei Province, China in December. Since then, there have been over 62300396 cases of COVID-19 infections worldwide, with 6550033 deaths. Therefore, it is important to avoid infection. In the absence of an effective treatment for coronavirus disease 2019 (COVID-19) non-pharmaceutical interventions are the only available methods of disease control. Social distancing, face masks, and personal hygiene are the most effective precautions, but maintaining these actions is not practicable in the long term. As a result, herd immunity by vaccination becomes the most effective eradication method, as in other viral epidemic diseases in the past. Research into development of a vaccine for SARS-CoV-2 was undertaken immediately after the disease was identified. The success of a vaccine depends not only on its efficacy, but also its acceptance. However, vaccine hesitancy has become an important threat to global health, which was pointed out by WHO in 2019.4 Several key factors behind vaccine hesitancy include fear or mistrust of the vaccine, underestimation of the value of the vaccine, and lack of access to the vaccine. Objective(s): To determine vaccine acceptance and hesitancy attitudes toward coronavirus disease 2019 (COVID-19) vaccines in pregnant women. Method(s): 250 pregnant women were surveyed face to face with 40 questions. Socio demographic characteristics, vaccination history, perception of risk for the COVID-19 pandemic, the impact of the COVID-19 pandemic, and acceptance of and attitude toward future COVID-19 vaccination were prospectively evaluated. Among all participants, 93 (37%) stated their intent to receive the vaccine if it were recommended for pregnant women. Most common refusal reasons were lack of data about COVID-19 vaccine safety in pregnant populations and possibility of harm to the fetus. Conclusion(s): The present study reported low acceptance of COVID- 19 vaccination in a sample of pregnant women. Concern about vaccine safety was the major reason for hesitancy. Identifying attitudes among priority groups will be useful for creating vaccination strategies that increase uptake during the current pandemic.

Quantifying Population Immunity to Covid-19 in Washington State and Oregon

Background: Since early 2020, the novel SARS-CoV-2 virus has spread rapidly throughout the globe. Subsequently many individuals have developed some form of immunity due to either a prior infection, one or more vaccinations, or a combination of the two. Using local epidemic data and mathematical modeling, we enumerate the various immune populations in Washington State and Oregon and quantify the level of protection against infection and hospitalization. Method(s): We developed a compartmental model of ordinary differential equations, which stratifies the population by age (0-17 years, 18-49 years, 50-64 years, and 65+ years), region, type of immunity (naive, infectionderived, vaccine-derived, booster-derived, hybrid immunity, etc), and recency of immune conferring event (recent and waned). To track the number of individuals in each category we combine 1) literature-based estimates of susceptibility to infection and severe disease by age, immune status, and variant, 2) calibration to the number of severe infections (hospitalizations and deaths) and number of vaccinations and 3) validation with serological surveys of the population. Result(s): We estimate that by mid-April 2022 more than 95% of the populations of both Washington and Oregon had some immunity against COVID-19 infection and hospitalization. Younger age groups tended to have much higher rates of natural or hybrid immunity with 96% of 0-17-year-olds and 83% of 18-49-year-olds protected due to past infections. Overall, the population-level immunity against the Omicron variant reduced risk of infection by 59% (95% Credible Interval 54% - 62%) and risk of hospitalization by 79% (95% CI 77% - 81%) in Washington and 62% (95% CI 57% -66%) and 83% (95% CI 82% - 85%), respectively, in Oregon. There was similar population-level protection against Delta at the start of the Omicron wave in early December 2021, which reduced risk of infection by 60% (95% CI 56% - 63%) and risk of hospitalization 79% (95% CI 78% - 80%) in Washington and 66% (95%CI 63% - 70%) and 82% (81% - 83%), respectively, in Oregon. Conclusion(s): Very large waves of new infections throughout 2021 and early 2022, in addition to high levels of vaccination and boosting among the older age groups in Washington and Oregon have greatly reduced population susceptibility to currently circulating strains. However even very high population immunity has allowed for emergence of novel variants that escape existing immunity, highlighting the need for continued develop of new variantspecific boosters.

A model for the SARS-CoV-2 dynamics in a population lacking herd immunity

We introduced the S-HI model, a generalized SEIR model to describe the dynamics of the SARS-CoV-2 virus in a community without herd immunity and performed simulations for six months. The S- HI model consists of eight equations corresponding to susceptible individuals, exposed, asymptomatic infected, asymptomatic recovered, symptomatic infected, quarantined, symptomatic recovered and dead. We study the dynamics of the infected, asymptomatic. Dead classes in 4 different networks: households, workplaces, agglomeration places and the general community, showing that the dynamics of the three compartments have the exact nature in each layer and that the speed of the disease considerably increases in the networks with the highest weight of contacts. The reproduction number, R0, is greater than 1 in all networks conforming to the theory. The variants of the SARS-Cov-2 virus are not taken into account, so the S-HI model would fit a situation similar to the first wave of contagion after the mandatory lockdown. Copyright: © 2022 by the authors.

CLUSTERING OF COVID-19 VACCINES BY SARS-CoV-2 INFECTION LEVEL AFTER TWO VACCINATIONS

Vaccination against COVID-19 is designed to provide herd immunity. However, there are cases of SARS-CoV-2 infection after vaccination. Using Python software, we calculated the number of SARS-CoV-2 infections per 100,000 adults after the first and second vaccinations as at July 23, 2021, conducted in St. Petersburg, Russian Federation. After the first vaccination with Gam-COVID-Vac (Sputnik V) vaccine, 544 infections were determined, and after the second vaccination -1,643 cases. After the first vaccination with the EpiVacCorona vaccine, 1,600 infections were calculated, and after the second vaccination -6,073 cases. After the first vaccination with CoviVac vaccine, 1,162 infections were determined, and after the second vaccination -886 cases. Cluster analysis revealed the similarity of epidemiological indicators due to Gam-COVID-Vac and CoviVac vaccines, with EpiVacCorona vaccine isolated in a separate cluster, which is associated with significant differences in the calculated epidemiological parameters.

Adaptive nonlinear controllers based approach to improve the frequency control of multi islanded interconnected microgrids

Islanded microgrids (MGs) are now widely used to electrify rural areas at a lesser cost and with greater efficiency. To maintain system balance and guarantee stability when exposed to various disturbances, MGs should be equipped with efficient controllers. Traditional controllers (like the PI controller) are linear and offer the best performance at a certain operating point, but the performance may degrade when the operating situation changes. To mitigate the drawbacks of fixed parameters controller, the paper suggested a fuzzy PI controller-based model reference adaptive control (FPI-MRAC) optimized by an advanced meta-heuristic optimization technique coronavirus herd immunity optimizer (CHIO) for enhancing the dynamic performance of several interconnected MGs. The proposed controller is non-linear adaptive controller that can improve the system performance over a wide range of operating conditions. The effectiveness of FPI-MRAC is assessed by subjecting the system to various disturbances, such as generation variation, load change, changing in uncertain system parameters and occurrence short circuit faults. Additionally, it investigated how quick reaction supercapacitors can improve the dynamic performance of the system. The acquired results show that, for all applied scenarios, the FPI-MRAC offers a much superior dynamic response than PI controller. Using super-capacitors also improves the system frequency when there are disruptions.

Blockchain Based Trading Mechanism in Microgrid using CHIO Algorithm

Blockchain based microgrid mechanisms can be designed efficiently to provide uninterrupted power supply and to balance load demands dynamically. In this present work, a conceptual design of a microgrid system is proposed in power system modeling. A blockchain based trading mechanism has been implemented on this system. Various optimization algorithms have been used to maximize economic profit. Finally, the Coronavirus Herd Immunity Optimizer (CHIO) algorithm is described to accommodate the impression that arises for the optimal power flow (OPF) and energy capacity. A case study has been provided to authenticate the performance of this method. The result expresses that the present scheme can largely improve the power dispatch and trading system. © 2022 IEEE.

Determination of control area and design of fuzzy rule-tuned PID controller for LFC of multimachine power system

In load frequency control (LFC) study of a large power system, the key concept is control area, which is the segment of the system consisting of strongly interconnected buses, generator buses thereof working in unison. For accurate linearization of load frequency control problem, proper determination of control area is important. In the present work, a novel deterministic method is proposed and formulated to calculate the sharing of load changes by the generators to determine the control areas for LFC study of multimachine systems. This method is applied on a weakly interconnected two-area system and then on the 10-Machine New England Test System for area segmentation of each of the two systems. Furthermore, LFC studies are carried out with proposed Fuzzy Rule-tuned PID controllers (FRT-PID Controllers) for both the systems incorporated with Dish-Stirling Solar thermal system (DSTS) in each area. The scaling factors and the controller gains are optimized using Coronavirus Herd Immunity Optimizer Algorithm (CHIOA). Performance of the proposed FRT-PID controllers is compared with that of the Conventional PID controllers for the LFC studies of the systems. To test effectiveness of the FRT-PID controllers, effect of random step load perturbation (SLP) in load buses located in different areas are considered. © 2023 Elsevier B.V.