Transmission Rate Of Virus Research Articles

Improvement in the 95-95-95 Targets Is Accompanied by a Reduction in Both the Human Immunodeficiency Virus Transmission Rate and Incidence in China.

In 2016, China has implemented the World Health Organization's "treat all" policy. We aimed to assess the impact of significant improvements in the 95-95-95 targets on population-level human immunodeficiency virus (HIV) transmission dynamics and incidence. We focused on 3 steps of the HIV care continuum: diagnosed, on antiretroviral therapy, and achieving viral suppression. The molecular transmission clusters were inferred using HIV-TRACE. New HIV infections were estimated using the incidence method in the European Centre for Disease Prevention and Control HIV Modelling Tool. Between 2004 and 2023, the national HIV epidemiology database recorded 2.99 billion person-times of HIV tests and identified 1 976 878 new diagnoses. We noted a roughly "inverted-V" curve in the clustering frequency, with the peak recorded in 2014 (67.1% [95% confidence interval, 63.7%-70.5%]), concurrent with a significant improvement in the 95-95-95 targets from 10-13-<71 in 2005 to 84-93-97 in 2022. Furthermore, we observed a parabolic curve for a new infection with the vertex occurring in 2010. In general, it was suggested that the improvements in the 95-95-95 targets were accompanied by a reduction in both the population-level HIV transmission rate and incidence. Thus, China should allocate more effort to the first "95" target to achieve a balanced 95-95-95 target.

A conformable mathematical model of Ebola Virus Disease and its stability analysis

Ebola Virus Disease (EVD) is a viral hemorrhagic fever that affects humans and other primates. It is characterized by rapid virus spread in a short period of time. The disease has the potential to spread to many different regions of the world. In this paper, we have developed a modified mathematical model of the Ebola virus, adding the quarantine population as a control strategy. The quarantine population F and parameters ρ3 represent the rate at which individuals enter the quarantine compartment, which is vital in controlling the virus spread within society. The conformable derivatives have been applied to the modified model to observe the behavior of individuals for fractional derivative values between 0.7 and 1. For a modified model, the threshold parameter (R0) has been determined using the Next-Generation Matrix (NGM) method. We have checked local and global stability at a disease-free equilibrium point using Routh-Herwitz (RH) criteria and Castillo-Chavez, respectively. Numerical results obtained through the Fourth-Order Runge Kutta Method (RK4) demonstrate, a decrease in the virus transmission rate after following the implementation of the quarantine strategy.

Bovine leukemia virus transmission rates in persistent lymphocytotic infected dairy cows.

Bovine leukemia virus (BLV) establishes a lifelong persistent infection in dairy cattle. White blood cell count (WBC) is correlated with proviral load in the blood and milk of BLV-infected cattle, and testing WBC can be used to assess both BLV infectiousness levels and risk of BLV transmission from different types of infected animals. The objective of the study was to compare effective transmission rates (β) and the basic reproduction ratio (R o) among two types of BLV-infected dairy cows in Chile: those affected with persistent lymphocytosis (PL) vs. aleukemic (AL).The estimated (β) coefficient was higher in PL cattle [1.1; 95% Confidence interval (CI) (-1.6, 3.8)], compared to AL cattle (-3.1; 95% CI = -3.7, -2.5). In addition, the R o was higher in PL cattle (60.4; 95% CI = 3.5; 820.6), compared to AL cattle (1.5; 95% CI = 0.7, 3.1). The ratio between PL/AL expected rate of cases was 73.9. The estimated effective transmission rate and the Ro were higher in PL cattle compared to AL cattle. The WBC test is a convenient alternative that can be considered for risk identification and risk management of BLV infection in dairy herds; particularly in livestock regions where laboratory capacity is limited (e.g., use of PCR or gene sequencing techniques) and/or molecular tests are not cost-effective. Therefore, when prevalence of infection is high, the removal of PL cattle should be engaged to control BLV within-herds.

Quantifying the Health–Economy Trade-Offs: Mathematical Model of COVID-19 Pandemic Dynamics

The COVID-19 pandemic has presented a complex situation that requires a balance between control measures like lockdowns and easing restrictions. Control measures can limit the spread of the virus but can also cause economic and social issues. Easing restrictions can support economic recovery but may increase the risk of virus transmission. Mathematical approaches can help address these trade-offs by modeling the interactions between factors such as virus transmission rates, public health interventions, and economic and social impacts. A study using a susceptible-infected-susceptible (SIS) model with modified discrete time was conducted to determine the cost of handling COVID-19. The results showed that, without government intervention, the number of patients rejected by health facilities and the cost of handling a pandemic increased significantly. Lockdown intervention provided the least number of rejected patients compared to social distancing, but the costs of handling the pandemic in the lockdown scenario remained higher than those of social distancing. This research demonstrates that mathematical approaches can help identify critical junctures in a pandemic, such as limited health system capacity or high transmission rates, that require rapid response and appropriate action. By using mathematical analysis, decision-makers can develop more effective and responsive strategies, considering the various factors involved in the virus’s spread and its impact on society and the economy.

Reduction in vertical transmission rate of bean common mosaic virus in bee-pollinated common bean plants

Vertical transmission, the transfer of pathogens across generations, is a critical mechanism for the persistence of plant viruses. The transmission mechanisms are diverse, involving direct invasion through the suspensor and virus entry into developing gametes before achieving symplastic isolation. Despite the progress in understanding vertical virus transmission, the environmental factors influencing this process remain largely unexplored. We investigated the complex interplay between vertical transmission of plant viruses and pollination dynamics, focusing on common bean (Phaseolus vulgaris). The intricate relationship between plants and pollinators, especially bees, is essential for global ecosystems and crop productivity. We explored the impact of virus infection on seed transmission rates, with a particular emphasis on bean common mosaic virus (BCMV), bean common mosaic necrosis virus (BCMNV), and cucumber mosaic virus (CMV). Under controlled growth conditions, BCMNV exhibited the highest seed transmission rate, followed by BCMV and CMV. Notably, in the field, bee-pollinated BCMV-infected plants showed a reduced transmission rate compared to self-pollinated plants. This highlights the influence of pollinators on virus transmission dynamics. The findings demonstrate the virus-specific nature of seed transmission and underscore the importance of considering environmental factors, such as pollination, in understanding and managing plant virus spread.

Molecular Docking of Phytochemicals from M. Charantia Targeting SARS-CoV-2 Main Protease

Coronavirus Disease 2019 (COVID-19) is a transmittable disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). The outbreak of the disease has affected the world in a negative manner. The development and on-going vaccination efforts has reduced the mortality rate in people with existing comorbidities and lowered virus transmission rate. However, there are still the needs for prescribed medicines that can be consumed by COVID-19 infected persons. Momordica charantia L. has been used in traditional medicines to treat various diseases including anti-diabetic and cancer. Pharmacological studies on Momordica charantia L. revealed that the plant stored many useful phytoconstituents that might be exploited for producing drug compounds to treat COVID-19. Nowadays, computational-aided drug methods are widely used in drug discovery process as it requires minimal compound design and improve the development pipeline. In this study, molecular docking of five phytochemicals from Momordica charantia L. were carried out against SARS-CoV-2 main protease (Mpro). The results obtained revealed that some of the phytochemicals showed a better dock score compared to the drug molnupiravir. Based on the dock score and the medicinal properties of each compound, it is suggested that these compounds can be further studied for potential drugs against COVID-19.

Transmission from seed to seedling and elimination of alfalfa viruses.

Viral diseases have become a vital factor limiting the development of the alfalfa (Medicago sativa) industry. Six viruses infecting alfalfa with a high incidence rate are Alfalfa mosaic virus (AMV), Medicago sativa alphapartitivirus 1 (MsAPV1), Medicago sativa alphapartitivirus 2 (MsAPV2), Medicago sativa deltapartitivirus 1 (MsDPV1), Medicago sativa amalgavirus 1 (MsAV1), and Cnidium vein yellowing virus 1 (CnVYV1). The purpose of this study was to develop preventive measures against these viruses by investigating their transmission through alfalfa seeds. In this study, we investigated the transmission rate of alfalfa viruses from seed to seedling by PCR, determined the location of viruses in seed by dissecting seed embryos and seed coat, tracked the changes of viruses in seedlings, and finally discover effective elimination measures for alfalfa viruses from 16 measures. Our results demonstrated that all these six viruses could be transmitted from alfalfa seeds to seedlings with the transmission rate ranging from 44.44% to 88.89%. For AMV, MsAPV2, and MsAV1, the viral load was significantly higher in the seed coats than in the seed embryos; however, it did not show significant differences between these two parts of the seeds for MsAPV1, MsDPV1, and CnVYV1. Dynamic accumulation analysis of AMV and MsAPV2 indicated that the viral load in plants increased continuously in the early growth stage, making it important to inactivate these viruses prior to their seed-to-seedling transmission. Sixteen treatments including physical, chemical, and combinations of physical and chemical measures were compared in terms of their elimination efficiency on AMV and MsAPV2 and impacts on seed germination. The results showed that soaking alfalfa seeds in sterile distilled water for 2h + 2% NaClO for 1h or 2% NaClO for 1h were more promisingly applicable because it could significantly reduce AMV and MsAPV2 particles in both seeds and seedlings. Our data revealed a route of virus transmission in alfalfa and shed light on the discovery of a highly efficient method for the management of alfalfa viral diseases.

Stochastic approach to a delayed in-host model of DENV transmission

Motivation. The immune response to the viral transmission experiences delays due to diverse biological factors and is affected by several factors. These include infection rate, rate of apoptosis and impact of the antibody-virus complex which exhibit unpredictable nature in a random environment. Objective. The main goal is to examine the impact of noise terms, introduced into every state variable, on a delayed in-host model of viral transmission. Methodology. To determine the intensity fluctuations and variances of all concerned state variables in the stochastic delayed model, which includes a constant delay and Gaussian white noise, the Fourier transformation method is employed. Results and Conclusions. The limiting value of the delay parameter is derived explicitly as well as numerically. The system experiences Hopf bifurcation, whenever the delay parameter crosses the limiting value which is shown graphically. The intensities and variances of different cells and virus populations are derived and the values are computed numerically. As the delay increases, the level of viremia decreases while other parameters maintain fixed values. The outcomes of data sensitivity, shown in graphical form, indicate that the transmission rate and supply rate of viruses are highly sensitive. Our findings suggest that the presence of noise causes fluctuations in the delayed model, leading to a noticeable impact on the transmission of the virus.

MATHEMATICAL MODEL OF REPELLENT EFFECT IN DENGUE TRANSMISSION

Dengue is a disease caused by the dengue virus, transmitted through the bite of an infected female Aedes aegypti. Dengue virus is a member of the genus Flavivirus, family Flaviviridae. Indonesia is one of the countries with the most dengue cases in Southeast Asia. Therefore, dengue transmission must be controlled to reduce the increase in dengue cases. One of the controls is by using repellents. Repellent is one of the human protection strategies to avoid mosquito bites used by spraying or smearing. This study models dengue transmission by reviewing the effect and control of repellent. A mathematical model of repellent effect and control in dengue transmission uses a SIR compartment model. The SIR model is modified by involving mosquitoes and the human population. Repellent is used in both susceptible humans, infected humans, and recovered humans. Numerical and analytical simulations are conducted to analyze the behavior of each compartment of the mosquito and human populations in dengue transmission. Analytical results show that the factors affecting the spread of infection are the transmission rate of the dengue virus and the loss of human-repellent protection. The transmission rate of dengue virus in the interval increases the infected human by 2.73%, while the rate of loss of human repellent protection in the interval increases the infected human by 0.03%. Optimal control is used to minimize the number of infected humans who do not use repellent. The results of numerical simulations on the optimal control problem show that an increase in the proportion of healthy humans who have campaign effect and use repellent regularly in the range of 14.67% can reduce infected individuals by 0.647%.

Relative Humidity-Dependent Phase Transitions in Submicron Respiratory Aerosols.

Respiratory viruses, such as influenza and severe acute respiratory syndrome coronavirus 2, represent a substantial public health burden and are largely transmitted through respiratory droplets and aerosols. Environmental factors such as relative humidity (RH) and temperature impact virus transmission rates, and a precise mechanistic understanding of the connection between these environmental factors and virus transmission would improve efforts to mitigate respiratory disease transmission. Previous studies on supermicrometer particles observed RH-dependent phase transitions and linked particle phase state to virus viability. Phase transitions in atmospheric aerosols are dependent on size in the submicrometer range, and actual respiratory particles are expelled over a large size range, including submicrometer aerosols that can transmit diseases over long distances. Here, we directly investigated the phase transitions of submicrometer model respiratory aerosols. A probe molecule, Nile red, was added to particle systems including multiple mucin/salt mixtures, a growth medium, and simulated lung fluid. For each system, the polarity-dependent fluorescence emission was measured following RH conditioning. Notably, the fluorescence measurements of mucin/NaCl and Dulbecco's modified Eagle's medium particles indicated that liquid-liquid phase separation (LLPS) also occurs in submicron particles, suggesting that LLPS can also impact the viability of viruses in submicron particles and thus affect aerosol virus transmission. Furthermore, the utility of fluorescence-based measurements to study submicrometer respiratory particle physicochemical properties in situ is demonstrated.

MicroRNA750-3p Targets Processing of Precursor 7 to Suppress Rice Black-Streaked Dwarf Virus Propagation in Vector Laodelphax striatellus.

MicroRNAs (miRNAs) are non-coding RNAs, which, as members of the RNA interference pathway, play a pivotal role in antiviral infection. Almost 80% of plant viruses are transmitted by insect vectors; however, little is known about the interaction of the miRNAs of insect vectors with plant viruses. Here, we took rice black-streaked dwarf virus (RBSDV), a devastating virus to rice production in eastern Asia, and the small brown planthopper, (SBPH, Laodelphax striatellus) as a model to investigate the role of microRNA750-3p (miR750-3p) in regulating viral transmission. Our results showed that Ls-miR750-3p was downregulated in RBSDV-infected SBPH and predominately expressed in the midgut of SBPH. Injection with miR750-3p agomir significantly reduced viral accumulation, and the injection with the miR750-3p inhibitor, antagomir-750-3p, dramatically promoted the viral accumulation in SBPH, as detected using RT-qPCR and Western blotting. The processing of precursor 7 (POP7), a subunit of RNase P and RNase MRP, was screened, identified, and verified using a dual luciferase reporter assay as one target of miR750-3p. Knockdown of POP7 notably increased RBSDV viral propagation in SBPH and then increased the viral transmission rate by SBPH. Taken together, our data indicate that miR750-3p targets POP7 to suppress RBSDV infection in its insect vector. These results enriched the role of POP7 in modulating virus infection in host insects and shared new insight into the function of miRNAs in plant virus and insect vector interaction.

The role of immune cells in resistance to oncolytic viral therapy.

Resistance to treatment poses a major challenge for cancer therapy, and oncoviral treatment encounters the issue of viral resistance as well. In this investigation, we introduce deterministic differential equation models to explore the effect of resistance on oncolytic viral therapy. Specifically, we classify tumor cells into resistant, sensitive, or infected with respect to oncolytic viruses for our analysis. Immune cells can eliminate both tumor cells and viruses. Our research shows that the introduction of immune cells into the tumor-virus interaction prevents all tumor cells from becoming resistant in the absence of conversion from resistance to sensitivity, given that the proliferation rate of immune cells exceeds their death rate. The inclusion of immune cells leads to an additional virus-free equilibrium when the immune cell recruitment rate is sufficiently high. The total tumor burden at this virus-free equilibrium is smaller than that at the virus-free and immune-free equilibrium. Therefore, immune cells are capable of reducing the tumor load under the condition of sufficient immune strength. Numerical investigations reveal that the virus transmission rate and parameters related to the immune response significantly impact treatment outcomes. However, monotherapy alone is insufficient for eradicating tumor cells, necessitating the implementation of additional therapies. Further numerical simulation shows that combination therapy with chimeric antigen receptor (CAR T-cell) therapy can enhance the success of treatment.

Surviving the summer: foot-and-mouth disease virus survival in U.S. regional soil types at high ambient temperatures.

Foot-and-mouth disease (FMD) is one of the most economically significant global livestock diseases. In the U.S., economic optimization models run in 2011 demonstrate the highest mean epidemic impact of a potential FMD outbreak in California would occur in livestock-dense regions, resulting in national agriculture losses of $2.3 to $69.0 billion. In the case that an FMD outbreak occurred in the U.S., mass depopulation, carcass disposal, and disinfection protocols for infected premises have been designed to prevent further viral spread. Because the FMD virus (FMDV) is spread mechanically via the environment, characteristics of viral environmental stability are important. Temperature and adsorption to soil particles are reported to be the most important factors affecting general virus survival; however, how much these factors alter FMDV survival has not been tested. Soil samples were examined from typical U.S. regions containing the highest cattle population densities: Tennessee, Georgia, Nebraska, California, Pennsylvania, Kentucky, and Iowa. Soils were spiked with known quantities of FMDV and FMDV stability was evaluated over seven distinct time points between 0 hours and 12 days at incubation temperatures of 25°C and 37°C to represent a range of typical ambient temperatures during the summer. FMDV stability was quantified via virus titration. Virus decayed faster at higher ambient temperatures for all soils, but decay at 25°C was faster in some soils. Consequently, areas with high ambient temperatures may have lower between-farm transmission rates, slower outbreak spread, and simpler farm decontamination. This study provides a helpful exploration into understanding soil survival of the virus. Additional investigations into FMDV survival across different soil types will aid in developing better disinfection protocols and further refining regional viral transmission rate estimates.

A Dynamic Model of Information‐Vaccination‐Disease That Accounts for Emerging Viral Variants: Model Development and a Case Study for COVID‐19 in Iceland

Pathogens mutate as diseases spread, and variants that become epidemic or pandemic strains have higher transmission rates and a greater capacity to escape vaccine protection. Considering different vaccine efficacy and vaccination rates is of great significance for the prevention and control of infectious diseases. The spread of vaccination information and the level of trust in vaccinations determine whether people will choose to be vaccinated. To analyze these factors, we developed mean‐field equations for system dynamics to model the complex system of vaccine information dissemination and vaccination, calculated the basic reproduction rate number, and used the Icelandic COVID‐19 outbreak (Omicron variant) as a case study. We found that in the face of emerging variants, increasing vaccine efficacy is more effective than increasing vaccination rates. If vaccine efficacy increases from 40% to 90%, infections can be decreased by 98.5%. However, even a 100% vaccination rate cannot stop the spread of a mutated virus if vaccine efficacy falls below a certain level. High vaccination rates decrease the virus transmission rate. If the efficacy of the vaccine diminishes, the infection will spread rapidly, leading to a greater number of individuals becoming infected with the infectious disease. Due to the high vaccine efficacy against major illnesses and fatalities, improving vaccination rates can lower deaths. Iceland could decrease deaths by 44.8% by raising the vaccination rate from 75.9% to 95.0%. To combat emerging virus variants, it is therefore necessary to both create more effective vaccines and raise awareness of the benefits of vaccination to increase vaccination rates.

Prenatal Infection by Respiratory Viruses Is Associated with Immunoinflammatory Responses in the Fetus.

Rationale: Respiratory viral infections can be transmitted from pregnant women to their offspring, but frequency, mechanisms, and postnatal outcomes remain unclear. Objectives: The aims of this prospective cohort study were to compare the frequencies of transplacental transmission of respiratory syncytial virus (RSV) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), analyze the concentrations of inflammatory mediators in maternal and fetal blood, and assess clinical consequences. Methods: We recruited pregnant women who developed upper respiratory infections or tested positive for SARS-CoV-2. Maternal and cord blood samples were collected at delivery. Study questionnaires and electronic medical records were used to document demographic and medical information. Measurements and Main Results: From October 2020 to June 2022, droplet digital PCR was used to test blood mononuclear cells from 103 mother-baby dyads. Twice more newborns in our sample were vertically infected with RSV compared with SARS-CoV-2 (25.2% [26 of 103] vs. 11.9% [12 of 101]; P = 0.019). Multiplex ELISA measured significantly increased concentrations of several inflammatory cytokines and chemokines in maternal and cord blood from newborns, with evidence of viral exposure in utero compared with control dyads. Prenatal infection was associated with significantly lower birth weight and postnatal weight growth. Conclusions: Data suggest a higher frequency of vertical transmission for RSV than SARS-CoV-2. Intrauterine exposure is associated with fetal inflammation driven by soluble inflammatory mediators, with expression profiles dependent on the virus type and affecting the rate of viral transmission. Virus-induced inflammation may have pathological consequences already in the first days of life, as shown by its effects on birth weight and postnatal weight growth.

A cost-effective label-free biosensor for rapid detection of multiple viral respiratory infections base on liquid crystals: Fabrication and modeling

The high transmission rate and incurability of recurrent Herpes Simplex Virus (HSV) infection require an accurate and fast detection approach for its efficient prevention. In an attempt to find a novel sensitive and simple optical diagnostic technique which enables on-spot testing, here we developed label-free biosensors based on E7 nematic liquid crystals (LCs) for specific detection of HSV DNA. For this purpose, homeotropically oriented LCs as smart materials are spread on the textile grid to make their both upper and lower surfaces be in contact with ambient air. HSV DNA of concentration between 1.4 nM and 5.5 nM is added to the platform, and DNA elution buffer is used as a control. Then, the reorientation of LCs occurs due to the coupling of electrical dipoles between LCs and DNA molecules. Creating a unique pattern that is projected onto CCD by putting the sample in a cross-polarizer and using white light. To model the LC's director distribution, LC's free energy equation is solved using the variational method and finite difference method (FDM). Overall, our LC-based sensor is a user-friendly, cost-effective, highly sensitive, and fast way for specific detection of HSV without the need for experts and expensive equipment.

Mortality in Norway and Sweden during the COVID-19 pandemic 2020–22: A comparative study

BackgroundNorway and Sweden picked two different ways to mitigate the dissemination of the SARS-CoV-2 virus. Norway introduced the strictest lockdown in Europe with strict border controls and intense virus tracking of all local outbreaks while Sweden did not. That resulted in 477 COVID-19 deaths (Norway) and 9737 (Sweden) in 2020, respectively. MethodsWeekly number of COVID-19 related deaths and total deaths for 2020–22 were collected as well as weekly number of deaths for 2015–19 which were used as controls when calculating excess mortality. During the first 12–18 months with high rate of virus transmission in the society, excess mortality rates were used as substitute for COVID-19 deaths. When excess mortality rates later turned negative because of mortality displacement, COVID-19 deaths adjusted for bias due to overreporting were used. ResultsThere were 17521 COVID-19 deaths in Sweden and 4272 in Norway in the study period. The rate ratio (RR) of COVID-19 related deaths in Sweden vs. Norway to the end of week 43, 2022, was 2.11 (95% CI 2.05–2.19). RR of COVID-19 related deaths vs. excess number of deaths were 2.5 (Sweden) and 1.3 (Norway), respectively. RR of COVID-19 deaths in Sweden vs. Norway after adjusting for mortality displacement and lockdown, was 1.35 (95% CI 1.31–1.39), corresponding to saving 2025 life in Norway. If including all deaths in 2022, RR= 1.28 (95% CI 1.24–1.31). ConclusionsBoth COVID-19 related mortality and excess mortality rates are biased estimates. When adjusting for bias, mortality differences declined over time to about 30% higher mortality in Sweden after 30 months with pandemics.

"We lost a lot, but something good came out of it too:" Exploring the impact of the COVID-19 pandemic on the mental wellbeing of British Muslim Pakistani women with family responsibilities.

The COVID-19 pandemic and associated restrictions caused major disruption globally, shedding light on the unprecedented strain upon the mental health and wellbeing of individuals around the world. Poor mental health in the pandemic is reported to be greater in women, with mothers being at increased risk. It is unclear whether there are differences in the impact of mental wellbeing on some ethnic groups over others. The aim of this study was to explore the experiences of British Muslim Pakistani women with family responsibilities during the COVID-19 pandemic, two years on from the first lockdown. Qualitative interviews with women were conducted via telephone using a semi-structured topic guide. The sample included 25 British Muslim Pakistani women with family responsibilities, both English and non-English speaking. Women lived in households that ranged in number and included extended family. Key themes were determined using thematic analysis. Results were grouped under three themes. These were (1) Community, cultural and religious contributors to poor mental wellbeing, (2) religious and cultural mediators of mental distress, and (3) perceived positive impact on lifestyle. British Muslim Pakistani women were psychologically distressed by the high rates of virus transmission and deaths in their communities and at the prospect of older members of their extended family developing the virus. The impact of restrictions on fundamental religious and cultural interactions further exacerbated poor mental wellbeing in this population. Religion, community social capital and larger household structures were all effective coping strategies for British Muslim Pakistani women. Positive impacts of the pandemic included becoming closer to family and faith, and increased work/life harmony. An exploration of religious and cultural coping mechanisms should be used to inform future national pandemic preparedness plans, as well as effective strategies for building and maintaining social capital. This may increase adherence to physical distancing and other protective behaviours in populations.

Different aspects in explaining how mutations could affect the binding mechanism of receptor binding domain of SARS-CoV-2 spike protein in interaction with ACE2.

During replication, some mutations occur in SARS-CoV-2, the causal agent of COVID-19, leading to the emergence of different variants of the virus. The mutations that accrue in different variants of the virus, influence the virus' ability to bind to human cell receptors and ability to evade the human immune system, the rate of viral transmission, and effectiveness of vaccines. Some of these mutations occur in the receptor binding domain (RBD) of the spike protein that may change the affinity of the virus for the ACE2 receptor. In this study, several in silico techniques, such as MD and SMD simulations, were used to perform comparative studies to deeply understand the effect of mutation on structural and functional details of the interaction of the spike glycoprotein of SARS-CoV-2, with the ACE2 receptor. According to our results, the mutation in the RBD associated with the Omicron variant increase binding affinity of the virus to ACE2 when compared to wild type and Delta variants. We also observed that the flexibility of the spike protein of the Omicron variant was lower than in comparison to other variants. In summary, different mutations in variants of the virus can have an effect on the binding mechanism of the receptor binding domain of the virus with ACE2.

A time-dependent SEIRS model for COVID-19 in China (mainland)

In the spring of 2022, two years after the onset of the coronavirus pandemic, a second worldwide outbreak is underway, with the number of patients infected with COVID-19 much higher than the peak during the first outbreak. Moreover, the second outbreak was not prevented in mainland China by a series of management measures with few local infections and mandatory quarantine of incoming persons. In this paper, we construct a compartmental model that includes exposed and isolated individuals to address the fact that the COVID-19 virus cannot be permanently immunized and to consider the isolation and treatment process in China. The model is used to analyze which factors have an impact on secondary outbreaks and uses the basic reproduction number to represent the outbreak. We obtained the expression for the basic reproduction number by calculating the basic reproduction number of the model. We used MATLAB to perform sensitivity analysis on each variable included in the expression for the basic reproduction number. In the sensitivity analysis, the increase in the basic reproduction number indicates that the rate of virus transmission and the rate of antibody failure are more critical to the pandemic. Reducing these rates can be effective in mitigating the epidemic. Also, the sensitivity analysis showed that increasing the vaccination rate does not help to reduce the basic reproduction number effectively. Therefore, the Chinese government should urge people to continue wearing masks to reduce the route and likelihood of the COVID-19 virus transmission and could appropriately reduce funding for vaccine promotion until a long-term effective vaccine is invented.