SARS-CoV-2 Delta variant: a systematic review of transmissibility and severity in children

Objectives: To review the evidence of the transmissibility and severity of infection with the Delta variant of SARS-CoV-2 in children. Design: Systematic review. Data sources: PubMed, Embase, medRxiv, Web of Science, and WHO COVID database. Study selection: English language original articles, case reports, commentaries, and letters with relevant primary data, which examined evidence for the transmissibility and severity of infection with the Delta variant of SARS-CoV-2 in children. Methods: Five databases were searched for articles from the period October 2020 to March 2022. Reference lists of eligible studies and grey literature were hand searched for additional studies for inclusion. Articles that provided adequate epidemiological data including infection, transmission, or severity (including hospitalisation and death) with probable or confirmed cases of the Delta variant of SARS-CoV-2 in children (aged ≤9 years) and adolescents (aged 10 to 19 years) were included. Data were extracted for country of origin;participant characteristics (age and sex);sample size;vaccination status;and outcomes, including incidence, secondary attack rate, hospitalisation, ICU, and mortality. All included studies were assessed for bias using the Joanna Briggs Institute Critical Appraisal checklists. Results: 298 studies were found through database searching. After screening, 21 studies were included in the systematic review. Of the included studies, all were deemed to be of moderate to high quality, therefore all were included in the final analysis. Increased incidence was reported in two population studies in the USA and Australia during the period of Delta predominance. Age-related data were available for 14 studies and showed higher rates of infection in older children compared to younger children. Attack rates in educational settings were higher when an adult was the primary case. Data on severity were available from 12 studies and showed that severe disease remained rare, with increasing hospitalisation numbers in proportion to increasing paediatric cases. Vaccination was protective for severe disease, with studies in the United States, Israel and Europe showing less healthcare encounters, emergency department presentations and hospitalisations amongst vaccinated adolescents. Several studies pointed to educational and household settings as key sites for paediatric infection with the Delta variant. Conclusion: A growing proportion of COVID-19 cases were diagnosed in children during the study period due to increased transmissibility of the SARS-CoV-2 Delta variant, with an increasing number of outbreaks observed in household and educational settings likely attributed to low vaccine coverage among children. While severe disease remains uncommon, the impact of vaccination in both adults and adolescents has been shown to reduce paediatric hospitalisation rates. © 2022 The Author(s).

Clinical Characteristics and Outcomes of Children With SARS-CoV-2 Infection During the Delta and Omicron Variant-Dominant Periods in Korea.

BACKGROUND: Data on the clinical characteristics of pediatric patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variant infection are limited. We aimed to evaluate the clinical features and outcomes of children with SARS-CoV-2 infection before and after omicron variant dominance in Korea. METHODS: A multicenter retrospective cohort study was conducted in hospitalized patients aged ≤ 18 years with laboratory-confirmed SARS-CoV-2 infection at five university hospitals in South Korea. The study periods were divided into the delta (from August 23, 2021 to January 2, 2022) and omicron (from January 30 to March 31, 2022). RESULTS: In total, 612 hospitalized patients were identified (211, delta; 401, omicron). During the omicron and delta periods, the proportions of individuals with serious illness (moderate, severe, and critical severity) were 21.2% and 11.8%, respectively (P = 0.034). Compared with the delta period, the proportions of patients with moderate illness increased significantly in the age groups of 0-4 years (14.2% vs. 3.4%) and 5-11 years (18.6% vs. 4.2%) during the omicron period. During the two periods, the proportions of patients with complex chronic diseases (delta, 16.0% vs. 4.3%, P = 0.040; omicron, 27.1% vs. 12.7%; P = 0.002), respiratory diseases except for asthma (delta, 8.0% vs. 0.0%, P = 0.013; omicron, 9.4% vs. 1.6%; P = 0.001), and neurologic diseases (delta, 28.0% vs. 3.2%, P < 0.001; omicron, 40.0% vs. 5.1%, P < 0.001) were significantly higher in patients with serious illness than in those with non-serious illness. During the delta period, the risk for serious illness was higher among patients with obesity (adjusted odds ratio [aOR], 8.18; 95% confidence interval [CI], 2.80-27.36) and neurologic diseases (aOR, 39.43; 95% CI, 6.90-268.3) and aged 12-18 years (aOR, 3.92; 95% CI, 1.46-10.85). However, the presence of neurologic disease (aOR, 9.80; 95% CI, 4.50-22.57) was the only risk factor for serious illness during the omicron period. During the omicron period, the proportions of patients with croup (11.0% vs. 0.5%) and seizures (13.2% vs. 2.8%) increased significantly compared with the delta period. CONCLUSION: Compared with the delta period, the proportions of young children and patients with complex comorbidities were higher during the omicron period in Korea. Patients with complex chronic diseases, especially neurologic diseases, had a high risk of severe coronavirus disease 2019 in the two distinct variant-dominant periods.

Clinical characteristics of patients infected with novel coronavirus wild strain, Delta variant strain and Omicron variant strain in Quanzhou: A real‑world study

This study aimed to investigate the clinical features of patients infected with novel coronavirus wild strains, Delta variant strains and Omicron variant strains to provide a reference for early clinical diagnosis and prognostic assessment. The demographic, clinical symptoms and ancillary examination data of 47 patients with novel coronavirus wild type strain infection, 18 with Delta variant infection and 20 with Omicron variant infection admitted to the First Hospital of Quanzhou affiliated with Fujian Medical University were collected and analyzed. The novel coronavirus wild strain and Delta strain were the predominant clinical types;patients infected with the Omicron strain were mainly asymptomatic. Fever and fatigue were the main clinical manifestations in the wild strain and Delta strain groups, whereas dry cough, nasal congestion, sore throat and fever were common clinical manifestations in the Omicron strain group. The Delta strain and Omicron variant groups had fewer comorbidities than the wild-type strain group, but no significant reduction was observed in the negative conversion time of nucleic acids. Significant differences were found in the neutrophil count/lymphocyte count ratio, lymphocyte count, eosinophil count, red blood cell count, hemoglobin level, erythrocyte sedimentation rate, C-reactive protein, prothrombin time, international normalized ratio and plasma D-dimer, PH, PaO2, lactic acid and albumin levels among the three groups. Patients infected with the Omicron strain in Quanzhou presented with mild symptoms of the upper respiratory tract as the primary clinical manifestation and had few comorbidities and a good prognosis;however, the negative conversion time of the new coronavirus nucleic acid was still considerably long. [ FROM AUTHOR] Copyright of Experimental & Therapeutic Medicine is the property of Spandidos Publications UK 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.)

The Real Estate: Lane Brown: What If the Rent Surge Is Based on a Lie? Investigating a COVID-era mystery

But a spokesperson told me ina statement, "Rent prices are driven primarilyby supply and demand, and in NewYork, vacancy is very low, causing rents torise." But this is only one factor in NewYork's rent-affordability crisis, and mothballingthese units probably isn't what sentthe price of market-rate Manhattan one-bedroomsspiraling toward infinity. Some argue--including the plaintiffs ofover a dozen class-action lawsuits filed in thewake of ProPublica's story--that RealPage'ssoftware allows individual landlords to keeptheir hands clean while indirectly colludingto inflate prices. The Real Estate: Lane Brown: What If the Rent Surge Is Based on a Lie?. [Extracted from the article] Copyright of New York is the property of New York Media 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.)

Divulging Incipient SARS-CoV-2 Delta (B.1.617.2) Variant: Possible Interference with Global Scenario.

SARS-CoV-2 Delta variant, also known as lineage B.1.617.2, is a variant of lineage B.1.617 of SARS-CoV-2, the virus that causes COVID-19. The B.1.617.2 variant was first discovered in India in December 2020, and by mid-April 2021, it had become the most often reported variant. On May 31, 2021, the World Health Organization (WHO) designated it as the Delta variation. Delta is 40-60% more transmissible than Alpha and nearly twice as transmissible as the original Wuhan strain of SARS-CoV-2, according to data. According to some evidence, the Delta variation may cause more severe illness in unprotected people than prior variants. A rapid increase in instances of this variation has been observed in the United Kingdom, which has been linked to travel from India and community transmission. WHO reports that the Delta version of Covid-19 has already been found in different countries throughout the world. According to the available information, the Delta variant appears to increase transmissibility, secondary attack rate, hospitalization risk, and immune escape. Due to the lack of data, the possible effects of the Delta variation on vaccination and treatment effectiveness remain unknown. However, neutralization efficiency in vaccinated people and resistance to monoclonal antibody therapy of the Delta variant have been documented in recent investigations.

Risk of paediatric multisystem inflammatory syndrome (PIMS-TS) during the SARS-CoV-2 alpha and delta variant waves: National observational and modelling study, 2020-21, England.

Objectives: Paediatric Multisystem Inflammatory Syndrome (PIMS-TS) is a rare life-threatening complication that typically occurs several weeks after SARS-CoV-2 infection in children and young people (CYP). We used national and regional-level data from the COVID-19 pandemic waves in England to develop a model to predict PIMS-TS cases. Methods: SARS-CoV-2 infections in CYP aged 0-15 years in England were estimated using the PHE-Cambridge real-time model. PIMS-TS cases were identified through the British Paediatric Surveillance Unit during (March-June 2020) and through Secondary Uses Services (SUS) from November 2020. A predictive model was developed to estimate PIMS-TS risk and lag times after SARS-CoV-2 infections. Results: During the Alpha wave, the model accurately predicted PIMS-TS cases (506 vs. 502 observed cases), with a median estimated risk of 0.038% (IQR, 0.037-0.041%) of paediatric SARS-CoV-2 infections. For the Delta wave, the median risk of PIMS-TS was significantly lower at 0.026% (IQR, 0.025-0.029%), with 212 observed PIMS-TS cases compared to 450 predicted by the model. Conclusions: The model accurately predicted national and regional PIMS-TS cases in CYP during the Alpha wave. PIMS-TS cases were 53% lower than predicted during the Delta wave. Further studies are needed to understand the mechanisms of the observed lower risk with the Delta variant.

Cross-immunity against SARS-COV-2 variants of concern in naturally infected critically ill COVID-19 patients.

Critically ill patients infected with SARS-CoV-2 display adaptive immunity, but it is unknown if they develop cross-reactivity to variants of concern (VOCs). We profiled cross-immunity against SARS-CoV-2 VOCs in naturally infected, non-vaccinated, critically ill COVID-19 patients. Wave-1 patients (wild-type infection) were similar in demographics to Wave-3 patients (wild-type/alpha infection), but Wave-3 patients had higher illness severity. Wave-1 patients developed increasing neutralizing antibodies to all variants, as did patients during Wave-3. Wave-3 patients, when compared to Wave-1, developed more robust antibody responses, particularly for wild-type, alpha, beta and delta variants. Within Wave-3, neutralizing antibodies were significantly less to beta and gamma VOCs, as compared to wild-type, alpha and delta. Patients previously diagnosed with cancer or chronic obstructive pulmonary disease had significantly fewer neutralizing antibodies. Naturally infected ICU patients developed adaptive responses to all VOCs, with greater responses in those patients more likely to be infected with the alpha variant, versus wild-type.

The effect of hoisting on variants of Hierarchical Delta Debugging

Minimizing failing test cases is an important preprocessing step on the path of debugging. If much of a test case that triggered a bug does not contribute to the actual failure, then the time required to fix the bug can increase considerably. However, test case reduction itself can be a time‐consuming task, especially if done manually. Therefore, automated minimization techniques have been proposed, the minimizing Delta Debugging and the Hierarchical Delta Debugging (HDD) algorithms being the most well known. In this paper, we investigated the input format of HDD, searching for structures that the algorithm cannot reduce. Motivated by the findings, we have created an algorithmic framework that enabled the use of transformations other than pruning. Furthermore, with the Transformation‐based Minimization framework, we propose to extend HDD and its coarse and recursive variants with a reduction method that does not prune subtrees but replaces them with compatible subtrees further down the hierarchy, called hoisting. We have evaluated various combinations of pruning and hoisting on multiple test suites and found that hoisting can help to further reduce the size of test cases by 27% on average and by 80% as best case compared with the baseline algorithm. [ FROM AUTHOR]

Investigation of SARS-CoV-2 lineages and mutations circulating in a university-affiliated hospital in South Korea analyzed using Oxford Nanopore MinION sequencing.

OBJECTIVES: Despite the introduction of vaccines, treatments, and massive diagnostic testing, the evolution of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has continued to overcome barriers that had slowed its previous spread. As the virus evolves towards increasing fitness, it is critical to continue monitoring the occurrence of new mutations that could evade human efforts to control them. METHODS: We performed whole-genome sequencing using Oxford Nanopore MinION sequencing on 58 SARS-CoV-2 isolates collected during the ongoing coronavirus disease 2019 pandemic at a tertiary hospital in South Korea and tracked the emergence of mutations responsible for massive spikes in South Korea. RESULTS: The differences among lineages were more pronounced in the spike gene, especially in the receptor-binding domain (RBD), than in other genes. Those RBD mutations could compromise neutralization by antibodies elicited by vaccination or previous infections. We also reported multiple incidences of Omicron variants carrying mutations that could impair the diagnostic sensitivity of reverse transcription-polymerase chain reaction-based testing. CONCLUSION: These results provide an understanding of the temporal changes of variants and mutations that have been circulating in South Korea and their potential impacts on antigenicity, therapeutics, and diagnostic escape of the virus. We also showed that the utilization of the nanopore sequencing platform and the ARTIC workf low can provide convenient and accurate SARS-CoV-2 genomic surveillance even at a single hospital.

A Recombinant VSV-Based Bivalent Vaccine Effectively Protects against Both SARS-CoV-2 and Influenza A Virus Infection.

COVID-19 and influenza are both highly contagious respiratory diseases that have been serious threats to global public health. It is necessary to develop a bivalent vaccine to control these two infectious diseases simultaneously. In this study, we generated three attenuated replicating recombinant vesicular stomatitis virus (rVSV)-based vaccine candidates against both SARS-CoV-2 and influenza viruses. These rVSV-based vaccines coexpress SARS-CoV-2 Delta spike protein (SP) bearing the C-terminal 17 amino acid (aa) deletion (SPΔC) and I742A point mutation, or the SPΔC with a deletion of S2 domain, or the RBD domain, and a tandem repeat harboring four copies of the highly conserved influenza M2 ectodomain (M2e) that fused with the Ebola glycoprotein DC-targeting/activation domain. Animal immunization studies have shown that these rVSV bivalent vaccines induced efficient humoral and cellular immune responses against both SARS-CoV-2 SP and influenza M2 protein, including high levels of neutralizing antibodies against SARS-CoV-2 Delta and other variant SP-pseudovirus infections. Importantly, immunization of the rVSV bivalent vaccines effectively protected hamsters or mice against the challenges of SARS-CoV-2 Delta variant and lethal H1N1 and H3N2 influenza viruses and significantly reduced respiratory viral loads. Overall, this study provides convincing evidence for the high efficacy of this bivalent vaccine platform to be used and/or easily adapted to produce new vaccines against new or reemerging SARS-CoV-2 variants and influenza A virus infections. IMPORTANCE Given that both COVID-19 and influenza are preferably transmitted through respiratory droplets during the same seasons, it is highly advantageous to develop a bivalent vaccine that could simultaneously protect against both COVID-19 and influenza. In this study, we generated the attenuated replicating recombinant vesicular stomatitis virus (rVSV)-based vaccine candidates that target both spike protein of SARS-Cov-2 Delta variant and the conserved influenza M2 domain. Importantly, these vaccine candidates effectively protected hamsters or mice against the challenges of SARS-CoV-2 Delta variant and lethal H1N1 and H3N2 influenza viruses and significantly reduced respiratory viral loads.

Characteristics of Patients Seeking Treatment for "Brain Fog" Secondary to Post-Acute Sequelae of COVID-19 (PASC) in the Deep South

Objective: Describe those with persistent neuropsychiatric symptoms seeking treatment for Post-Acute Sequelae of COVID-19 (PASC). Method: Patients were referred for neuropsychological evaluation from the University of Alabama at Birmingham (UAB) Post-COVID Treatment Program. Ninety-seven patients completed a comprehensive set of self-report questionnaires. Results: Patients were 49 years old (range: 18 to 74), had 15.49 years (SD = 2.43) of education, and identified as female (77%), married (51%), and White/Caucasian (73%) or Black/AA (25%). Reported annual income ranged from ≤ $20,000 (11%) to ≥ $100,000 (32%), with 75% currently employed. Confirmed positive test result for COVID-19 was reported in 88%, with 87% having the original virus and 13% the Delta variant, based on estimated dates of infection. Symptoms during the acute illness included: headache (76%), fever (51%), cough (57%), shortness of breath (56%), and loss of smell or taste (54%). Most of the participants were not hospitalized (76%) nor required oxygen therapy (78%). Persistent symptoms included: headache (55%), shortness of breath (53%), muscle and joint pain (53%), cough (17%), congestion (40%) and loss of smell or taste (25%). Of these participants, 87% reported they had not returned to their baseline health because of COVID-19 and most indicated impaired job performance following COVID-19 infection. Conclusion: Those who sought treatment for persistent neuropsychiatric symptoms following a symptomatic course of COVID-19 were commonly middle aged, White, women, with at least a high school education. "Brain fog" secondary to PASC can result in reported persistent health and neuropsychiatric issues that can impact ability to work. [ FROM AUTHOR] Copyright of Archives of Clinical Neuropsychology is the property of Oxford University Press / USA 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.)

A Mathematical Model for a Transmissible Disease with a Variant

The outbreak of the Coronavirus (COVID-19) pandemic around the world has caused many health and socioeconomic problems, and the identification of variants like Delta and Omicron with similar and often even more transmissible modes of transmission has motivated us to do this study. In this article, we have proposed and analyzed a mathematical model in order to study the effect of health precautions and treatment for a disease transmitted by contact in a constant population. We determined the four equilibria of the system of ordinary differential equations representing the model and characterized their existence using exact methods of algebraic geometry and computer algebra. The model is studied using the stability theory for systems of differential equations and the basic reproduction number R 0 . The stability of the equilibria is analyzed using the Lienard-Chipart criterion and Lyapunov functions. The asymptotic or global stability of endemic equilibria is established, and the disease-free equilibrium is globally asymptotically stable if R 0 < 1. Model simulation is done with Python software to study the effects of health precautions and treatment, and the results are analyzed. It is observed that if the rate of treatment and compliance with health precautions are high, the number of infections decreases in the classes of infectious and is canceled out over time. It is concluded that the high treatment rate accompanied by a suitable rate of compliance with health precautions allows for the control the disease. [ FROM AUTHOR] Copyright of Journal of Applied Mathematics is the property of Hindawi Limited 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.)

A Chess and Card Room-Induced COVID-19 Outbreak and Its Agent-Based Simulation in Yangzhou, China.

Objective: To evaluate epidemiological characteristics of the COVID-19 outbreak that resurged in Yangzhou and to simulate the impact of different control measures at different regional scales. Methods: We collected personal information from 570 laboratory-confirmed cases in Yangzhou from 28 July to 26 August 2021, and built a modified susceptible-exposed-infected-removed (SEIR) model and an agent-based model. Results: The SEIR model showed that for passengers from medium-high risk areas, pre-travel nucleic acid testing within 3 days could limit the total number of infected people in Yangzhou to 50; among elderly persons, a 60% increase in vaccination rates could reduce the estimated infections by 253. The agent-based model showed that when the population density of the chess and card room dropped by 40%, the number of infected people would decrease by 54 within 7 days. A ventilation increase in the chess and card room from 25 to 50% could reduce the total number of infections by 33 within 7 days; increasing the ventilation from 25 to 75% could reduce the total number of infections by 63 within 7 days. Conclusions: The SEIR model and agent-based model were used to simulate the impact of different control measures at different regional scales successfully. It is possible to provide references for epidemic prevention and control work.

Impact of the SARS-CoV-2 Delta Variant on the Psychological States and Health-Related Quality of Life in Patients With Crohn's Disease.

Background: Since the outbreak of the coronavirus disease 2019 (COVID-19) pandemic first reported in Wuhan, China, several research on the psychological impact of the pandemic on patients with Crohn's disease (CD) have been conducted. However, with the progression of the global pandemic and the emergence of the SARS-CoV-2 B.1.617.2 (Delta) variant, follow-up studies need to be performed to monitor the alterations of psychological status and health-related quality of life (HRQoL) among CD patients. Aims: We aimed to evaluate the impact of the SARS-CoV-2 Delta variant on the mental health and life quality among the CD population and tried to explore potent risk factors. Methods: This observational study included 153 CD patients who responded to our pre-designed self-reported questionnaire. Demographic, clinical, and psychological information were collected and analyzed. Results: Quite a number of CD patients were confronted with different levels of anxiety and depression, with incidence of 28.10 and 31.37% for anxiety and depression, respectively. Compared with non-pandemic circumstances, the life quality of CD patients due to the present situation was more often compromised. Isolation [odds ratio (OR): 4.71, P = 0.007] was verified as a risk factor for anxiety while use of telemedicine could help relieve anxiety (OR: 0.22, P < 0.001). Worsening of symptoms (OR: 4.92, P = 0.006), isolation (OR: 5.75, P = 0.005), and drug withdrawn (OR: 2.66, P = 0.026) were identified to be independent factors for developing depression. Likewise, use of telemedicine (OR: 0.13, P < 0.001) was negatively related to depression. Considering life quality, vaccination (OR: 3.07, P = 0.021) together with no medication (OR: 7.73, P = 0.010) was relevant to better life quality while worsening of symptoms (OR: 0.09, P = 0.034) were an independent risk factor for impaired life quality. Conclusion: Many CD patients suffered from symptoms of anxiety and depression and impaired life quality during the COVID-19 pandemic. Those in isolation or with worsening of symptoms and drug withdrawn were more prone to experience psychological stress. Individualized management such as drug delivery and telemedicine should be promoted to maintain control of mental health and life quality during the pandemic.

SARS-CoV-2 variants and the global pandemic challenged by vaccine uptake during the emergence of the Delta variant: A national survey seeking vaccine hesitancy causes.

BACKGROUND: Herd immunity for COVID-19 is the ultimate goal to end the pandemic. Emergence of SARS-CoV-2 variants has been a subject of considerable debate regarding vaccines effectiveness. This ongoing discussion and other evolving variables contribute to the hesitancy toward vaccines and levels of vaccination acceptance among both the healthcare workers and the public. This study was conducted to assess COVID-19 vaccine uptake and hesitancy among the Saudi Arabian population during the emergence of SARS-CoV-2 Delta variant. METHODS: A national cross-sectional survey conducted between June 28 and July 5, 2021. The survey collected sociodemographic information, personal and family history of previous COVID-19 infection, adherence to precautionary measures, COVID-19 vaccination status, parental willingness to vaccinate their teenage children, and address variable associated with hesitancy to receive vaccination. RESULTS: Among the 4071 participants, 67 % were women, 86 % of the participants received COVID-19 vaccine, 70 % had very high or high commitment with COVID-19 precautionary measures. On multivariate analysis, vaccine hesitancy was less likely in men (OR 0.652, p-value < 0.001), those who had direct family members infected with COVID-19 (OR 0.455, p-value < 0.001), and those who reported using the Ministry of Health official channels as information sources (OR 0.522, p-value < 0.001), while those younger than 44 years had higher hesitancy to receive the vaccine (1.5-2.1 times). Of the participants, only 42 % showed willingness to vaccinate their teenage (12-18 years old) children. CONCLUSIONS: The participants in this study had high COVID-19 vaccination rate; however, hesitancy was reported more commonly among women. Their willingness to vaccinate their teenage children was much lower. Participants relying on social media platforms were highly hesitant to receive vaccination. Public health officials should scale up their efforts targeting females, young population, and parents by vaccination awareness campaigns, and refute misinformation spread on social media, especially with the emergence of variants and the news burst that coincide with them.