COVID-19 rhapsody:Rage towards advanced diagnostics and therapeutic strategy

The deadly global outbreak of coronavirus disease-2019(COVID-19)has forged an unrivaled threat to human civilization.Contemplating its profuse impact,initial risk management and therapies are needed,as well as rapid detection strategies alongside treatments with existing drugs or traditional treatments to provide better clinical support for critical patients.Conventional detection techniques have been considered but do not sufficiently meet the current challenges of effective COVID-19 diagnosis.Therefore,several modern techniques including point-of-care diagnosis with a biosensor,clustered regularly interspaced short palindromic repeats(CRISPR)-associated proteins that function as nuclease(Cas)technology,next-generation sequencing,serological,digital,and imaging approaches have delivered improved and noteworthy success compared to that using traditional strategies.Conventional drug treatment,plasma therapy,and vaccine development are also ongoing.However,alternative medicines including Ayurveda,herbal drugs,homeopathy,and Unani have also been enlisted as prominent treatment strategies for developing herd immunity and physical defenses against COVID-19.All considered,this review can help develop rapid and simplified diagnostic strategies,as well as advanced evidencebased modern therapeutic approaches that will aid in combating the global pandemic.

Optimization of Head Cluster Selection in WSN by Human-Based Optimization Techniques

Wireless sensor networks(WSNs)are characterized by their ability to monitor physical or chemical phenomena in a static or dynamic location by collecting data,and transmit it in a collaborative manner to one or more processing centers wirelessly using a routing protocol.Energy dissipation is one of the most challenging issues due to the limited power supply at the sensor node.All routing protocols are large consumers of energy,as they represent the main source of energy cost through data exchange operation.Clusterbased hierarchical routing algorithms are known for their good performance in energy conservation during active data exchange in WSNs.The most common of this type of protocol is the Low-Energy Adaptive Clustering Hierarchy(LEACH),which suffers from the problem of the pseudo-random selection of cluster head resulting in large power dissipation.This critical issue can be addressed by using an optimization algorithm to improve the LEACH cluster heads selection process,thus increasing the network lifespan.This paper proposes the LEACH-CHIO,a centralized cluster-based energyaware protocol based on the Coronavirus Herd Immunity Optimizer(CHIO)algorithm.CHIO is a newly emerging human-based optimization algorithm that is expected to achieve significant improvement in the LEACH cluster heads selection process.LEACH-CHIO is implemented and its performance is verified by simulating different wireless sensor network scenarios,which consist of a variable number of nodes ranging from 20 to 100.To evaluate the algorithm performances,three evaluation indicators have been examined,namely,power consumption,number of live nodes,and number of incoming packets.The simulation results demonstrated the superiority of the proposed protocol over basic LEACH protocol for the three indicators.

Reasons of Vaccine Hesitancy among Pakistanis with Available COVID-19 Vaccine: The Next Challenge in the Fight against COVID-19

The government of Pakistan started vaccination campaign for the frontline healthcare pro-viders, as they are more likely to be exposed to COVID-19 patients. In the next step, it ex-tended the free vaccination campaign to include people above 60 and 50 years of age re-spectively. The drive is now open to all citizens >18 years of age. There is a significant re-luctance to get vaccinated even though the government has provided it free of cost. The project uses self-reporting method to assess reasons of vaccine hesitancy among Pakistanis and possible solutions to overcome this problem. Concern for serious side effects was the most common issue 154 (48.42%) reported among all groups of people, including the healthcare workers. The major sources of COVID-19 related information were television 117 (36.8%) and healthcare professionals 105 (33%). The participants reported that they can be convinced to get vaccinated if more published data related to vaccine efficacy and safety is available 118 (37.1%), they observe no side effect among vaccine recipients 90 (28.3%) or higher government officials get the same vaccine 39 (12.3%). Vigorous analysis and publication of data generated is paramount to increase the percentage of people being vaccinated. The healthcare professionals should share evidence-based knowledge related to vaccine efficacy and safety through television and social media to increase acceptance rates and hence, decrease mortality and morbidity from COVID-19 in Pakistan.

Will vaccine-derived protective immunity curtail COVID-19 variants in the US?

Multiple effective vaccines are currently being deployed to combat the COVID-19 pandemic,and are viewed as the major factor in marked reductions of disease burden in regions with moderate to high vaccination coverage.The effectiveness of COVID-19 vaccination programs is,however,significantly threatened by the emergence of new SARS-COV-2 variants that,in addition to being more transmissible than the wild-type(original)strain,may at least partially evade existing vaccines.A two-strain(one wildtype,one variant)and two-group(vaccinated or otherwise)mechanistic mathematical model is designed and used to assess the impact of the vaccine-induced cross-protective efficacy on the spread the COVID-19 pandemic in the United States.Rigorous analysis of the model shows that,in the absence of any co-circulating SARS-CoV-2 variant,the vaccine-derived herd immunity threshold needed to eliminate the wild-type strain can be achieved if 59%of the US population is fully-vaccinated with either the Pfizer or Moderna vaccine.This threshold increases to 76%if the wild-type strain is co-circulating with the Alpha variant(a SARS-CoV-2 variant that is 56%more transmissible than the wild-type strain).If the wild-type strain is co-circulating with the Delta variant(which is estimated to be 100%more transmissible than the wild-type strain),up to 82%of the US population needs to be vaccinated with either of the aforementioned vaccines to achieve the vaccine-derived herd immunity.Global sensitivity analysis of the model reveal the following four parameters as the most influential in driving the value of the reproduction number of the variant strain(hence,COVID-19 dynamics)in the US:(a)the infectiousness of the co-circulating SARS-CoV-2 variant,(b)the proportion of individuals fully vaccinated(using Pfizer or Moderna vaccine)against the wild-type strain,(c)the cross-protective efficacy the vaccines offer against the variant strain and(d)the modification parameter accounting for the reduced infectiousness of fully-vaccinated individuals experiencing breakthrough infection.Specifically,numerical simulations of the model show that future waves or surges of the COVID-19 pandemic can be prevented in the US if the two vaccines offer moderate level of cross-protection against the variant(at least 67%).This study further suggests that a new SARS-CoV-2 variant can cause a significant disease surge in the US if(i)the vaccine coverage against the wild-type strain is low(roughly<66%)(ii)the variant is much more transmissible(e.g.,100%more transmissible),than the wild-type strain,or(iii)the level of cross-protection offered by the vaccine is relatively low(e.g.,less than 50%).A new SARS-CoV-2 variant will not cause such surge in the US if it is only moderately more transmissible(e.g.,the Alpha variant,which is 56%more transmissible)than the wild-type strain,at least 66%of the population of the US is fully vaccinated,and the three vaccines being deployed in the US(Pfizer,Moderna,and Johnson&Johnson)offer a moderate level of cross-protection against the variant.

The effect of mixed vaccination rollout strategy:A modelling study

Vaccines have measurable efficacy obtained first from vaccine trials.However,vaccine efficacy(VE)is not a static measure and long-term population studies are needed to evaluate its performance and impact.COVID-19 vaccines have been developed in record time and the currently licensed vaccines are extremely effective against severe disease with higher VE after the full immunization schedule.To assess the impact of the initial phase of the COVID-19 vaccination rollout programmes,we used an extended Susceptible-Hospitalized-Asymptomatic/mild-Recovered(SHAR)model.Vaccination models were proposed to evaluate different vaccine types:vaccine type 1 which protects against severe disease only but fails to block disease transmission,and vaccine type 2 which protects against both severe disease and infection.VE was assumed as reported by the vaccine trials incorporating the difference in efficacy between one and two doses of vaccine administration.We described the performance of the vaccine in reducing hospitalizations during a momentary scenario in the Basque Country,Spain.With a population in a mixed vaccination setting,our results have shown that reductions in hospitalized COVID-19 cases were observed five months after the vaccination rollout started,from May to June 2021.Specifically in June,a good agreement between modelling simulation and empirical data was well pronounced.

Global trends in COVID-19

The pandemic COVID-19 is certainly one of the most severe infectious diseases in human history.In the last 2 years,the COVID-19 pandemic has caused over 418.6 million confirmed cases and 5.8 million deaths world-wide.Young people make up the majority of all infected COVID-19 cases,but the mortality rate is relatively lower compared to older age groups.Currently,about 55.04%individuals have been fully vaccinated rapidly approaching to herd immunity globally.The challenge is that new SARS-CoV-2 variants with potential to evade immunity from natural infection or vaccine continue to emerge.Breakthrough infections have occurred in both SARS-CoV-2 naturally infected and vaccinated individuals,but breakthrough infections tended to exhibit mild or asymptomatic symptoms and lower mortality rates.Therefore,immunity from natural infection or vaccination can reduce SARS-CoV-2 pathogenicity,but neither can completely prevent SARS-CoV-2 infection/reinfection.Fortunately,the morbidity and mortality of COVID-19 continue to decline.The 7-day average cumulative case fatality of COVID-19 has decreased from 12.3%on the February 25,2020,to 0.27%on January 09,2022,which could be related to a decreased SARS-CoV-2 variant virulence,vaccine immunization,and/or better treatment of patients.In conclusion,elimination of SARS-CoV-2 in the world could be impossible or at least an arduous task with a long way to go.The best strategy to prevent COVID-19 pandemic is to expand inoculation rate of effective vaccines.As the population reaches herd immunity,the mortality rate of COVID-19 may continue to decrease,and COVID-19 could eventually become another common cold.

The impact of age structure and vaccine prioritization on COVID-19 in West Africa

The ongoing COVID-19 pandemic has been a major global health challenge since its emergence in 2019.Contrary to early predictions that sub-Saharan Africa(SSA)would bear a disproportionate share of the burden of COVID-19 due to the region's vulnerability to other infectious diseases,weak healthcare systems,and socioeconomic conditions,the pandemic's effects in SSA have been very mild in comparison to other regions.Interestingly,the number of cases,hospitalizations,and disease-induced deaths in SSA remain low,despite the loose implementation of non-pharmaceutical interventions(NPIs)and the low availability and administration of vaccines.Possible explanations for this low burden include epidemiological disparities,under-reporting(due to limited testing),climatic factors,population structure,and government policy initiatives.In this study,we formulate a model framework consisting of a basic model(in which only susceptible individuals are vaccinated),a vaccine-structured model,and a hybrid vaccine-age-structured model to assess the dynamics of COVID-19 in West Africa(WA).The framework is trained with a portion of the confirmed daily COVID-19 case data for 16 West African countries,validated with the remaining portion of the data,and used to(i)assess the effect of age structure on the incidence of COVID-19 in WA,(ii)evaluate the impact of vaccination and vaccine prioritization based on age brackets on the burden of COVID-19 in the sub-region,and(iii)explore plausible reasons for the low burden of COVID-19 in WA compared to other parts of the world.Calibration of the model parameters and global sensitivity analysis show that asymptomatic youths are the primary drivers of the pandemic in WA.Also,the basic and control reproduction numbers of the hybrid vaccine-age-structured model are smaller than those of the other two models indicating that the disease burden is overestimated in the models which do not account for age-structure.This result is confirmed through the vaccine-derived herd immunity thresholds.In particular,a comprehensive analysis of the basic(vaccine-structured)model reveals that if 84%(73%)of the West African populace is fully immunized with the vaccines authorized for use in WA,vaccine-derived herd immunity can be achieved.This herd immunity threshold is lower(68%)for the hybrid model.Also,all three thresholds are lower(60%for the basic model,51%for the vaccine-structured model,and 48%for the hybrid model)if vaccines of higher efficacies(e.g.,the Pfizer or Moderna vaccine)are prioritized,and higher if vaccines of lower efficacy are prioritized.Simulations of the models show that controlling the COVID-19 pandemic in WA(by reducing transmission)requires a proactive approach,including prioritizing vaccination of more youths or vaccination of more youths and elderly simultaneously.Moreover,complementing vaccination with a higher level of mask compliance will improve the prospects of containing the pandemic.Additionally,simulations of the model predict another COVID-19 wave(with a smaller peak size compared to the Omicron wave)by mid-July 2022.Furthermore,the emergence of a more transmissible variant or easing the existing measures that are effective in reducing transmission will result in more devastating COVID-19 waves in the future.To conclude,accounting for age-structure is important in understanding why the burden of COVID-19 has been low in WA and sustaining the current vaccination level,complemented with the WHO recommended NPIs is critical in curbing the spread of the disease in WA.

An evaluation of mathematical models for the outbreak of COVID-19

Mathematical modelling performs a vital part in estimating and controlling the recent outbreak of coronavirus disease 2019(COVID-19).In this epidemic,most countries impose severe intervention measures to contain the spread of COVID-19.The policymakers are forced to make difficult decisions to leverage between health and economic development.How and when tomake clinical and public health decisions in an epidemic situation is a challenging question.The most appropriate solution is based on scientific evidence,which is mainly dependent on data and models.So one of the most critical problems during this crisis is whether we can develop reliable epidemiological models to forecast the evolution of the virus and estimate the effectiveness of various intervention measures and their impacts on the economy.There are numerous types of mathematical model for epidemiological diseases.In this paper,we present some critical reviews on mathematical models for the outbreak of COVID-19.Some elementary models are presented as an initial formulation for an epidemic.We give some basic concepts,notations,and foundation for epidemiological modelling.More related works are also introduced and evaluated by considering epidemiological features such as disease tendency,latent effects,susceptibility,basic reproduction numbers,asymptomatic infections,herd immunity,and impact of the interventions.