Herd Immunity Research Articles

COVID Stress Factors, Willingness to be Vaccinated, and Reasons for Vaccination Hesitancy Amongst Youth and Ethnic Minorities: A Structural Equation Modeling Analysis

COVID-19 has caused psychological trauma. However, it is unclear whether these stresses are comparable across ethnicities, across age groups, and vaccination hesitancy. Moreover, the relationship between the different types of stresses and their relationship to vaccination hesitancy has not been studied. Using rigorous statistical methodology (structural equation modeling), we examined the measurement invariance of five COVID stress factors: danger of contamination, socioeconomic consequences, xenophobia, traumatic stress, compulsive checking, by ethnicity and age, and investigated their relationship to vaccination hesitancy, ethnicity, age, and expectations of contracting COVID using structural equation models on a UK sample. The instrument showed measurement invariance both with respect to ethnicity and vaccination hesitancy. Subjects with more stress and worry about contracting COVID had no more enthusiasm for getting vaccinated than the less stressed. Ethnic minorities were less stressed despite suffering higher morbidity and mortality. As age increases, so does the hesitancy to be vaccinated despite younger subjects reporting more compulsive checking. Vaccination hesitancy was related to fear of side effects and safety concerns. Public health campaigns should target younger populations to address their fears about and stress due to compulsive checking for COVID-19. These campaigns should also be designed to reduce vaccination hesitancy to increase vaccination rates, decrease active and passive carriers of the virus, and ultimately attain herd immunity.

Estimation of the adverse effects following immunization after SARS-CoV-2 Vaccine (Covishield and Covaxin) in lactating women: A single centre exploratory study from India

ABSTRACT Context: The global COVID-19 pandemic has universally impacted individuals, with lactating women being uniquely susceptible to severe infection. Vaccination plays a critical role in building population immunity, mitigating severe illness and curtailing the health crisis. However, data on adverse effects and vaccine safety in lactating women remains scarce. Aims: To assess the prevalence and types of adverse effects post-COVID vaccination in lactating women. Methods: This study was conducted at a tertiary care hospital’s COVID-19 vaccination centre in North India, and followed a prospective observational design over a specific timeframe. A total of 200 lactating women were surveyed, with specific inclusion and exclusion criteria applied. Telephonic follow-up was conducted for one month after the first dose for 152 participants and after the second dose for 123 participants. Adverse effects following immunization (AEFIs) were recorded and analyzed. Results: Of the study cohort, 45 (29.60%) reported minor adverse effects following the first vaccine dose, with just four (3.25%) experiencing adverse effects after the second dose. Common AEFIs included fever (18.42%) and body aches (9.21%), along with headache, malaise, injection site pain and diffuse abdominal pain. Conclusions: This study provides valuable insights into the adverse effects of COVID-19 vaccines in lactating women, which can help primary physicians and policy maker to improve vaccination policies and guidelines. The study revealed that lactating mothers experienced only mild AEFIs, aligning with current literature. Further broader, multicentre research is needed to reinforce these findings and to assess the long-term safety and efficacy of COVID-19 vaccines in this population.

Chemotherapy Enriches for Proinflammatory Macrophage Phenotypes that Support Cancer Stem-Like Cells and Disease Progression in Ovarian Cancer.

High-grade serous ovarian cancer remains a poorly understood disease with a high mortality rate. Although most patients respond to cytotoxic therapies, a majority will experience recurrence. This may be due to a minority of drug-resistant cancer stem-like cells (CSC) that survive chemotherapy and are capable of repopulating heterogeneous tumors. It remains unclear how CSCs are supported in the tumor microenvironment (TME) particularly during chemotherapy exposure. Tumor-associated macrophages (TAM) make up half of the immune population of the ovarian TME and are known to support CSCs and contribute to cancer progression. TAMs are plastic cells that alter their phenotype in response to environmental stimuli and thus may influence CSC maintenance during chemotherapy. Given the plasticity of TAMs, we studied the effects of carboplatin on macrophage phenotypes using both THP1- and peripheral blood mononuclear cell (PBMC)-derived macrophages and whether this supports CSCs and ovarian cancer progression following treatment. We found that carboplatin exposure induces an M1-like proinflammatory phenotype that promotes SOX2 expression, spheroid formation, and CD117+ ovarian CSCs, and that macrophage-secreted CCL2/MCP-1 is at least partially responsible for this effect. Depletion of TAMs during carboplatin exposure results in fewer CSCs and prolonged survival in a xenograft model of ovarian cancer. This study supports a role for platinum-based chemotherapies in promoting a transient proinflammatory M1-like TAM that enriches for CSCs during treatment. Improving our understanding of TME responses to cytotoxic drugs and identifying novel mechanisms of CSC maintenance will enable the development of better therapeutic strategies for high-grade serous ovarian cancer. Significance: We show that chemotherapy enhances proinflammatory macrophage phenotypes that correlate with ovarian cancer progression. Given that macrophages are the most prominent immune cell within these tumors, this work provides the foundation for future translational studies targeting specific macrophage populations during chemotherapy, a promising approach to prevent relapse in ovarian cancer.

Single-Cell Profiling of Peripheral Blood Mononuclear Cell Identifies Immune Populations Associated with Progression of Diabetic Kidney Disease

Single-Cell Profiling of Peripheral Blood Mononuclear Cell Identifies Immune Populations Associated with Progression of Diabetic Kidney Disease

Factors Associated With Appropriateness of Vaccination Age Coverage For Measles Vaccine In Kufa District, Najaf Governorate, Iraq

Measles is one of the diseases that can be effectively managed with vaccination. Herd immunity is a concept that describes the situation where a large proportion of a population is vaccinated, resulting in high coverage rates. Measles infections persist at high levels in specific areas despite the general vaccination rates. Administering the vaccination at the recommended age is crucial for attaining protection and reducing the transmission of vaccine-preventable illnesses . Cross –sectional study was conducted from 1st of OCT .2023 until 25th of JAN. 2024 among mothers with their child aged 12-23 month. The purpose of this study was to assess age-appropriate measles vaccination coverage and associated factors. Collected data using pre-tested questionnaires also data on measles vaccination were taken from vaccination card.This study analyzed 388 mothers, revealing that the majority of father age were between 20-34y, with 41.2% having primary education. Mother age found to be 258(66.5%) between 20-34y .225(57.9%) of father occupation were free job and 334(86.1%) were house wife by occupation, the sex of child 201(51.8%) were found to be female .68.61% were vaccinated with measles vaccine on time, (29.38%) were delayed and (1.80%) were found to be unvaccinated. The education level, number of children in the family and child order are significantly associated with measles vaccination status of child. As we revealed that the proportion of individuals receiving the vaccine within the designated timeframe is below 70%. We should focus on enhancing on time of routine children immunization. This can be achieved by reinforcing existing techniques, developing new approaches, and emphasizing the media's role in promoting the significance of timely vaccine administration.

Exploring key determinants of COVID-19 vaccine hesitancy among individuals: An exploratory study globally.

SARS-CoV-2 virus gave rise to COVID-19 in late 2019 in Wuhan, China, and it quickly spread over the world to become a pandemic. The virus, which is mostly carried by respiratory droplets, spread at an unprecedented rate, causing a large number of deaths and extensive illness, necessitating lockdowns, travel bans, and social distancing policies by governments across the globe in an attempt to stop the spread, which severely disrupted daily life, the healthcare system, and economies.COVID-19 vaccines are biological materials designed to offer protection against the organism that causes the COVID-19 pandemic, SARS-CoV-2 virus, played a crucial role in stopping the virus's spread and lowering the burden on healthcare systems around the globe. Although Covid-19 vaccines offers benefits which includes the prevention of severe illness and death through the reduction of the chance of COVID-19-related serious illness, hospital stays, and death, it was met with hesitancy by some population on the basis of a complex web of interrelated causes, such as political division, misinformation, socioeconomic inequities, and past mistrust of healthcare systems.Vaccine hesitancy contributed to lower-than-expected vaccination coverage in many regions, preventing the achievement of herd immunity and allowing the virus to continue spreading. Exploring this key determinants of Covid-19 vaccine hesitancy among individuals all over the world and possible solutions, is the focus of this research.

Tuft cells in the intestine, immunity and beyond.

Tuft cells have gained substantial attention over the past 10 years due to numerous reports linking them with type 2 immunity and microorganism-sensing capacity in many mucosal tissues. This heightened interest is fuelled by their unique ability to produce an array of biological effector molecules, including IL-25, allergy-related eicosanoids, and the neurotransmitter acetylcholine, enabling downstream responses in diverse cell types. Operating through G protein-coupled receptor-mediated signalling pathways reminiscent of type II taste cells in oral taste buds, tuft cells emerge as chemosensory sentinels that integrate luminal conditions, eliciting appropriate responses in immune, epithelial and neuronal populations. How tuft cells promote tissue alterations and adaptation to the variety of stimuli at mucosal surfaces has been explored in multiple studies in the past few years. Since the initial recognition of the role of tuft cells, the discovery of diverse tuft cell effector functions and associated feedback loops have also revealed the complexity of tuft cell biology. Although earlier work largely focused on extraintestinal tissues, novel genetic tools and recent mechanistic studies on intestinal tuft cells established fundamental concepts of tuft cell activation and functions. This Review is an overview of intestinal tuft cells, providing insights into their development, signalling and interaction modules in immunity and other states.

No impact of COVID-19 at delivery on maternal mortality or infant adverse birth outcomes in Botswana during the Omicron era.

SARS-CoV-2 infection during pregnancy was associated with maternal mortality and adverse birth outcomes in the pre-Omicron era, including a stillbirth rate of 5.6% in Botswana. We re-evaluated these outcomes in the Tsepamo Study during the Omicron era. We assessed maternal mortality and adverse birth outcomes for all singleton pregnancies from mid-November 2021 (the start of the Omicron era) to mid-August 2022 at nine Tsepamo sites, among individuals with documented SARS-CoV-2 screening PCR or antigen tests and known HIV status. Of 9,705 women routinely screened for SARS-CoV-2 infection at delivery (64% of deliveries at these sites), 373 (3.8%) tested positive. Women with HIV were as likely to test positive for SARS-CoV-2 (77/1833, 4.2%) as women without HIV (293/6981, 4.2%) (p = 1.0). There were 5 recorded maternal deaths (0.03%), one occurring in a woman with a positive SARS-CoV-2 test result. In contrast, maternal mortality was 3.7% and 0.1% in those with and without SARS-CoV-2, respectively, during the pre-Omicron era. In the Omicron era, there were no differences among infants exposed or unexposed to SARS-CoV-2 in overall adverse birth outcomes (28.1% vs 29.6%; aRR 1.0, 95%CI 0.8-1.1), severe adverse birth outcomes (11.9 vs 10.6%; aRR 1.1, 95%CI 0.8-1.5), preterm delivery (15.1% vs 14.9%; aRR 1.0, 95%CI 0.8-1.3), or stillbirth (1.9% vs 2.3%; aRR 0.8, 95%CI 0.4-1.7). Adverse outcomes among those exposed to both HIV and SARS-CoV-2 were similar to those exposed to HIV alone (31.2% vs. 33.1%; aRR 0.9, 95%CI 0.6-1.3; p = 0.5). Maternal mortality was far lower in Botswana during the Omicron era than in the pre-Omicron era, and adverse birth outcomes were no longer significantly impacted by exposure to SARS-CoV-2 either overall or with HIV co-exposure. Increased population immunity to SARS-CoV-2, less stress on the hospital systems in the Omicron era, and possible differences in viral pathogenicity may combine to explain these findings.

The effect of intrauterine growth restriction on the developing pancreatic immune system.

Immune cells in the pancreas are known to participate in organ development. However, the resident pancreatic immune system has yet to be fully defined. Immune cells also play a role in pathology and are implicated in diseases such as diabetes induced by intrauterine growth restriction (IUGR). We hypothesized that the resident immune system is established during neonatal development and disrupted by IUGR. Using single cell RNAseq and flow cytometry we identified many immune cell populations in the near-term fetus (at embryologic day 22) and neonatal (postnatal day 1, 7, &14) islets, non-endocrine pancreas, and the spleen in the rat. Using flow cytometry, we observed the resident immune system is established during neonatal development in the pancreas and spleen. We identified 9 distinct immune populations in the pancreatic islets and 8 distinct immune populations in the spleen by single cell RNAseq. There were no sex-specific differences in the relative proportion of immune cells in the pancreas or spleen. Finally, we tested if IUGR disrupted the neonatal immune system using bilateral uterine artery ligation. We found significant changes to the percentage of CD11B+ HIS48- and CD8+ T cells in the islets and non-endocrine pancreas and in the spleen. IUGR-induced alterations were influenced by the tissue environment and the sex of the offspring. Future research to define the role of these immune cells in pancreatic development may identify disrupted pathways that contribute to the development of diabetes following IUGR.

Application and Significance of SIRVB Model in Analyzing COVID-19 Dynamics.

In the summer of 2024, COVID-19 positive cases spiked in many countries, but it is no longer a deadly pandemic thanks to global herd immunity to the SARS-CoV-2 viruses. In our physical chemistry lab in spring 2024, students practice kinetic models, SIR (Susceptible, Infected, and Recovered) and SIRV (Susceptible, Infected, Recovered, Vaccinated) using COVID-19 positive cases and vaccination data from World Health Organization (WHO). In this report, we further introduce virus breakthrough to the existing model updating it the SIRVB (Susceptible, Infectious, Recovered, Vaccinated, Breakthrough) model. We believe this is the simplest model possible to explain the COVID-19 kinetics in all countries in the past four years. Parameters obtained from such practice correlate with many indices of different countries. These models and parameters have significant value to researchers and policymakers in predicting the stages of future outbreaks of infectious diseases.

Exploring Important Attributes, the Potential Use Cases and Feasibility of Introduction of Measles and Rubella Microarray Patches (MR-MAPs): Insights from Nine Countries.

Background: Microarray patches (MAPs) are innovative, needle-free vaccine delivery systems, suitable for administration by minimally trained health care workers or trained community health workers. Their introduction may transform immunization programmes, particularly for vaccines where high coverage is required for population immunity, such as measles, and where vaccine delivery is challenging, such as in low- and middle-income countries. Recognizing the need to understand how best to tailor these products to reflect country priorities, workshops on measles and rubella MAPs (MR-MAPs) were conducted in multiple regions to collect insights on needs and preferences from relevant stakeholders at country level. Methods: The CAPACITI Innovation Framework was used to structure stakeholder discussions in nine countries in the period from August 2022 to July 2023. The discussions, building on the findings from a situation analysis on the barriers related to measles and rubella vaccine delivery, followed the four-step process outlined in the framework. Results: Key barriers hindering delivery of measles and rubella vaccines across the countries were in the categories of human resource management, service delivery, and demand generation. MR-MAP attributes that stakeholders believed would reduce or eliminate these barriers included ease of preparation and administration, improved thermostability, fewer (ancillary) components, and single-dose presentation. Some attributes such as the site of administration, wear time, and storage volume could exacerbate certain barriers. Based on an understanding of key barriers, product attributes, and underserved populations, stakeholders identified several potential use cases for MR-MAPs: (i) delivery at a fixed health post, (ii) delivery through outreach sessions conducted by health workers, and (iii) administration by community health workers. To enable robust national decision making about the introduction of MR-MAPs and successful implementation, global and national evidence on feasibility and acceptability of MR-MAPs should be generated. To prepare for the potential introduction of MR-MAPs, immunization programmes should evaluate their immunization policies based on their preferred use cases and modify them if needed, for example, to enable community health workers to administer vaccines, along with making programmatic adjustments to waste management and training. Conclusions: MR-MAPs have the potential to reduce key barriers to MR delivery. Yet, their future impact depends on the ability of global stakeholders to steer the development of MR-MAPs to be responsive to country needs and preferences. The generation of evidence to enable robust decision making, timely modification of vaccine policies, and addressing programmatic considerations will be key to successful uptake.

Rapid Lactic Acid Content Detection in Secondary Fermentation of Maize Silage Using Colorimetric Sensor Array Combined with Hyperspectral Imaging

Lactic acid content is a crucial indicator for evaluating maize silage quality, and its accurate detection is essential for ensuring product quality. In this study, a quantitative prediction model for the change of lactic acid content during the secondary fermentation of maize silage was constructed based on a colorimetric sensor array (CSA) combined with hyperspectral imaging. Volatile odor information from maize silage samples with different days of aerobic exposure was obtained using CSA and recorded by a hyperspectral imaging (HSI) system. Subsequently, the acquired spectral data were subjected to preprocessing through five distinct methods before being modeled using partial least squares regression (PLSR). The coronavirus herd immunity optimizer (CHIO) algorithm was introduced to screen three color-sensitive dyes that are more sensitive to changes in lactic acid content of maize silage. To minimize model redundancy, three algorithms, such as competitive adaptive reweighted sampling (CARS), were used to extract the characteristic wavelengths of the three dyes, and the combination of the characteristic wavelengths obtained by each algorithm was used as an input variable to build an analytical model for quantitative prediction of the lactic acid content by support vector regression (SVR). Moreover, two optimization algorithms, namely grid search (GS) and crested porcupine optimizer (CPO), were compared to determine their effectiveness in optimizing the parameters of the SVR model. The results showed that the prediction accuracy of the model can be significantly improved by choosing appropriate pretreatment methods for different color-sensitive dyes. The CARS-CPO-SVR model had better prediction, with a prediction set determination coefficient (RP2), root mean square error of prediction (RMSEP), and a ratio of performance to deviation (RPD) of 0.9617, 2.0057, and 5.1997, respectively. These comprehensive findings confirm the viability of integrating CSA with hyperspectral imaging to accurately quantify the lactic acid content in silage, providing a scientific and novel method for maize silage quality testing.

Differences in PCV13 Recommendation Practices between Pediatric Care Providers and Primary Care Providers in China: A Cross-Sectional Survey of Behavior and Social Drivers.

Objectives: This study examines the recommendation behaviors and influencing factors for the 13-valent Pneumococcal Conjugate Vaccine (PCV13) among 3579 Chinese healthcare workers (HCWs), including 1775 pediatric care providers (Peds-PCPs) and 1804 primary care providers (PCPs). Data were collected from May to July 2023 through a national cross-sectional survey using a structured questionnaire, distributed across hospitals providing pediatric services in five provincial-level administrative divisions. Methods: The sociodemographic data, vaccine knowledge, and recommendation practices were analyzed using Pearson's chi-square test, Wilcoxson rank-sum test, and multivariate logistic regression. Results show that while PCPs are more likely to recommend PCV13, vaccine hesitancy persists among Peds-PCPs. Logistic regression revealed that higher influenza vaccination intention, salary, vaccine consultation frequency, familiarity with immunization, work ethic, and flexible schedules positively impacted HCWs' recommendation behavior. Results: Factors influencing Peds-PCPs' recommendations include vaccine training (OR: 1.470, CI: 1.049-2.509), safety recognition (OR: 1.986, CI: 1.163-3.391), concern over rejection (OR = 1.274, CI: 1.076-1.508) and vaccine cost (OR = 1.203, CI: 1.023-1.414). For PCPs, influencing factors were the perceived susceptibility of children to pneumonia (OR = 2.185, CI: 1.074-4.445), acceptance of herd immunity (OR: 1.717, CI: 1.101-2.677), and belief that parents with better family conditions are more likely to accept vaccine recommendations (OR = 1.229, CI: 1.024-1.477). Conclusion: This survey underscores the need for tailored interventions to address differing perceptions and enhance confidence in the safety and efficacy of vaccines among HCWs, particularly Peds-PCPs.

Comprehensive Spatial-Temporal and Risk Factor Insights for Optimizing Livestock Anthrax Vaccination Strategies in Karnataka, India.

Anthrax, a zoonotic disease affecting both livestock and humans globally, is caused by Bacillus anthracis. The objectives of this study were the following: (1) to identify environmental risk factors for anthrax and use this information to develop an improved predictive risk map, and (2) to estimate spatial variation in basic reproduction number (Ro) and herd immunity threshold at the village level, which can be used to optimize vaccination policies within high-risk regions. Based on the anthrax incidences from 2000-2023 and vaccine administration figures between 2008 and 2022 in Karnataka, this study depicted spatiotemporal pattern analysis to derive a risk map employing machine learning algorithms and estimate Ro and herd immunity threshold for better vaccination coverage. Risk factors considered were key meteorological, remote sensing, soil, and geographical parameters. Spatial autocorrelation and SaTScan analysis revealed the presence of hotspots and clusters predominantly in the southern, central, and uppermost northern districts of Karnataka and temporal cluster distribution between June and September. Factors significantly associated with anthrax were air temperature, surface pressure, land surface temperature (LST), enhanced vegetation index (EVI), potential evapotranspiration (PET), soil temperature, soil moisture, pH, available potassium, sulphur, and boron, elevation, and proximity to waterbodies and waterways. Ensemble technique with random forest and classification tree models were used to improve the prediction accuracy of anthrax. High-risk areas are expected in villages in the southern, central, and extreme northern districts of Karnataka. The estimated Ro revealed 11 high-risk districts with Ro > 1.50 and respective herd immunity thresholds ranging from 11.24% to 55.47%, and the assessment of vaccination coverage at the 70%, 80%, and 90% vaccine efficacy levels, all serving for need-based strategic vaccine allocation. A comparison analysis of vaccinations administered and vaccination coverage estimated in this study is used to illustrate difference in the supply and vaccine force. The findings from the present study may support in planning preventive interventions, resource allocation, especially of vaccines, and other control strategies against anthrax across Karnataka, specifically focusing on predicted high-risk regions.

Zinc pathogenic importance in correcting immunity and restoring public health in the post-COVID period: An overview

Context: The problem of correcting immune system function and compensating for co-morbidities becomes particularly clinically significant in the post-COVID period. There is evidence that certain trace elements in the human body, particularly zinc ions, play a critical role in restoring the function of the immune system and internal organs. Objective: To analyze the mechanisms of zinc action maintaining the body homeostasis in order to justify pathogenetically the inclusion of zinc drugs in the therapy of patients in the post-COVID period. Methods: Data from Elsevier, Global Health, PubMed-NCBI, Embase, MEDLINE, Scopus, Research gate, RSCI Scopus, Cochrane Library, Google Academy, e-LIBRARY.RU and CyberLeninka were used. Results: This review showed that the importance of zinc in maintaining body homeostasis in the post-COVID period is determined by its multifaceted effect on all parts of the immune system, its anti-inflammatory activity, antimicrobial properties and participation in the restoration of internal organ function. Elimination of zinc deficiency in the post-COVID period is essential to support immunity, compensate for comorbidities and reduce the risk of complications. The impossibility of synthesizing zinc in the body requires its constant intake in sufficient quantities. Zinc levels are significantly reduced after infectious diseases, as this element is specifically distributed to organs and tissues to maintain immunological and metabolic functions. The degree of zinc deficiency is associated with the severity of COVID-19 and the post-COVID period. It is pathogenetically justified to prescribe zinc drugs in the post-COVID period, the choice of which should take into account comorbidities and severity of hypozincemia. Conclusion: Regularly administered therapy with zinc drugs in the post-COVID period will help correct the population immunity and restore public health.

COVID-19 mutations: An overview.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) belongs to the genus Beta coronavirus and the family of Coronaviridae. It is a positive-sense, non-segmented single-strand RNA virus. Four common types of human coronaviruses circulate globally, particularly in the fall and winter seasons. They are responsible for 10%-30% of all mild upper respiratory tract infections in adults. These are 229E, NL63 of the Alfacoronaviridae family, OC43, and HKU1 of the Betacoronaviridae family. However, there are three highly pathogenic human coronaviruses: SARS-CoV-2, Middle East respiratory syndrome coronavirus, and the latest pandemic caused by the SARS-CoV-2 infection. All viruses, including SARS-CoV-2, have the inherent tendency to evolve. SARS-CoV-2 is still evolving in humans. Additionally, due to the development of herd immunity, prior infection, use of medication, vaccination, and antibodies, the viruses are facing immune pressure. During the replication process and due to immune pressure, the virus may undergo mutations. Several SARS-CoV-2 variants, including the variants of concern (VOCs), such as B.1.1.7 (Alpha), B.1.351 (Beta), B.1.617/B.1.617.2 (Delta), P.1 (Gamma), and B.1.1.529 (Omicron) have been reported from various parts of the world. These VOCs contain several important mutations; some of them are on the spike proteins. These mutations may lead to enhanced infectivity, transmissibility, and decreased neutralization efficacy by monoclonal antibodies, convalescent sera, or vaccines. Mutations may also lead to a failure of detection by molecular diagnostic tests, leading to a delayed diagnosis, increased community spread, and delayed treatment. We searched PubMed, EMBASE, Covariant, the Stanford variant Database, and the CINAHL from December 2019 to February 2023 using the following search terms: VOC, SARS-CoV-2, Omicron, mutations in SARS-CoV-2, etc. This review discusses the various mutations and their impact on infectivity, transmissibility, and neutralization efficacy.

Relationship between Livestock Vaccination Programs and Mortality Rates in India

Purpose: To aim of the study was to analyze the relationship between livestock vaccination programs and mortality rates in India. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: Vaccination programs for livestock in India significantly reduce mortality rates, particularly in cattle, sheep, and goats. Comprehensive vaccination decreases the incidence of infectious diseases, enhances herd immunity, and improves overall productivity. Regions with strong vaccination coverage see better livestock health and increased farmer livelihoods. Economic analyses show that the benefits of reduced mortality and increased productivity often outweigh the costs, highlighting the need for ongoing investment in veterinary health services and education to promote widespread vaccination. Unique Contribution to Theory, Practice and Policy: Health belief model (HBM), theory of planned behavior (TPB) & diffusion of innovations theory may be used to anchor future studies on the relationship between livestock vaccination programs and mortality rates in India. Practically, there is a need to strengthen the infrastructure for vaccine distribution, especially in remote and underserved areas. Policymakers should develop and enforce policies that support the expansion and optimization of livestock vaccination programs.

Genomic characterization of highly pathogenic H5 avian influenza viruses from Alaska during 2022 provides evidence for genotype-specific trends of spatiotemporal and interspecies dissemination

: The ongoing panzootic of highly pathogenic H5 clade 2.3.4.4b avian influenza (HPAI) spread to North America in late 2021, with detections of HPAI viruses in Alaska beginning in April 2022. HPAI viruses have since spread across the state, affecting many species of wild birds as well as domestic poultry and wild mammals. To better understand the dissemination of HPAI viruses spatiotemporally and among hosts in Alaska and adjacent regions, we compared the genomes of 177 confirmed HPAI viruses detected in Alaska during April – December 2022. Results suggest multiple viral introductions into Alaska between November 2021 and August or September 2022, as well as dissemination to areas within and outside of the state. Viral genotypes differed in their spatiotemporal spread, likely influenced by timing of introductions relative to population immunity. We found evidence for dissemination of HPAI viruses between wild bird species, wild birds and domestic poultry, as well as wild birds and wild mammals. Continued monitoring for and genomic characterization of HPAI viruses in Alaska can improve our understanding of the evolution and dispersal of these economically costly and ecologically relevant pathogens.

A Modified SIVR Mathematical Model of Covid-19 Post-vaccination Stability Analysis in Kenya

In this paper, the study focused on carrying out a stability analysis on a modified SIR model for the COVID-19 pandemic for the period after vaccination in Kenya. The purpose of the work was to show that whereas the rate and the extent of disease spread amongst the Kenyan people was not as wide spread as happened in other parts of the world, it was necessary for government and policy makers to roll out a robust civic education to convince the majority of the Kenyan population to embrace vaccination as a major containment measure in curbing the spread of COVID-19 and other infectious diseases since the study revealed that the infections drastically reduced to near zero after vaccination except for a few isolated cases that were and still continue to exhibit mild symptoms to none at all. This was attributed to the development of the vaccine which upon a massive campaign by the Kenyan government, led into a significant portion of the population being vaccinated. It is believed this vaccination drive enhanced herd immunity amongst the population. This development has had a significant effect in the control of more recent COVID-19 variants like JN-1 that have remained largely mild and undetected in the country. Both local and global post vaccination stabilities were analyzed for the system using the Lyapunov function. The main objective of the study was therefore to carry out a post vaccination stability analysis by estimating key parameters such as the basic reproduction number, ( R0) and herd immunity threshold (HIT) for infectious diseases by fitting data into the model to enable predictions of future dynamics of the disease. The study used the Next Generation matrix and the least square method besides the Python software to solve generated differential equations of the model for and HIT parameters. Results obtained showed that, there was a significant reduction in infections due to enhanced herd immunity attributed largely to the roll out of vaccination.

Increasing Population Immunity Prior to Globally-Coordinated Cessation of Bivalent Oral Poliovirus Vaccine (bOPV).

In 2022, global poliovirus modeling suggested that coordinated cessation of bivalent oral poliovirus vaccine (bOPV, containing Sabin-strain types 1 and 3) in 2027 would likely increase the risks of outbreaks and expected paralytic cases caused by circulating vaccine-derived polioviruses (cVDPVs), particularly type 1. The analysis did not include the implementation of planned, preventive supplemental immunization activities (pSIAs) with bOPV to achieve and maintain higher population immunity for types 1 and 3 prior to bOPV cessation. We reviewed prior published OPV cessation modeling studies to support bOPV cessation planning. We applied an integrated global poliovirus transmission and OPV evolution model after updating assumptions to reflect the epidemiology, immunization, and polio eradication plans through the end of 2023. We explored the effects of bOPV cessation in 2027 with and without additional bOPV pSIAs prior to 2027. Increasing population immunity for types 1 and 3 with bOPV pSIAs (i.e., intensification) could substantially reduce the expected global risks of experiencing cVDPV outbreaks and the number of expected polio cases both before and after bOPV cessation. We identified the need for substantial increases in overall bOPV coverage prior to bOPV cessation to achieve a high probability of successful bOPV cessation.