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1.
Multimedia | Multimedia Resources | ID: multimedia-9782

ABSTRACT

O vídeo apresenta informações sobre como o pico de contaminação acontece. O aplicativo FioLibras é um projeto do Instituto de Comunicação e Informação Científica e Tecnológica em Saúde da Fundação Oswaldo Cruz (Icict/Fiocruz), em parceria com o Núcleo de Estudos em Diversidade e Inclusão de Surdos da Universidade Federal Fluminense (Nuedis/UFF), e conta com financiamento do Fundo de Inovação da Fiocruz e do Ministério da Saúde, por meio do Programa Fiocruz de Fomento à Inovação (Inova Fiocruz).


Subject(s)
COVID-19/transmission , Coronavirus Infections , Information Dissemination , Sign Language , e-Accessibility
2.
Multimedia | Multimedia Resources | ID: multimedia-9800

ABSTRACT

Quando não é mais possível identificar quem é o transmissor da doença. O aplicativo FioLibras é um projeto do Instituto de Comunicação e Informação Científica e Tecnológica em Saúde da Fundação Oswaldo Cruz (Icict/Fiocruz), em parceria com o Núcleo de Estudos em Diversidade e Inclusão de Surdos da Universidade Federal Fluminense (Nuedis/UFF), e conta com financiamento do Fundo de Inovação da Fiocruz e do Ministério da Saúde, por meio do Programa Fiocruz de Fomento à Inovação (Inova Fiocruz).


Subject(s)
Disease Transmission, Infectious , COVID-19/transmission , Coronavirus Infections , Information Dissemination , Sign Language , e-Accessibility
3.
Multimedia | Multimedia Resources | ID: multimedia-9802

ABSTRACT

O vídeo apresenta informações sobre como uma pessoa não-infectada pode acidentalmente ser infectada por uma doença. O aplicativo FioLibras é um projeto do Instituto de Comunicação e Informação Científica e Tecnológica em Saúde da Fundação Oswaldo Cruz (Icict/Fiocruz), em parceria com o Núcleo de Estudos em Diversidade e Inclusão de Surdos da Universidade Federal Fluminense (Nuedis/UFF), e conta com financiamento do Fundo de Inovação da Fiocruz e do Ministério da Saúde, por meio do Programa Fiocruz de Fomento à Inovação (Inova Fiocruz).


Subject(s)
COVID-19/transmission , Coronavirus Infections , Information Dissemination , Sign Language , e-Accessibility
4.
Virulence ; 13(1): 1242-1251, 2022 12.
Article in English | MEDLINE | ID: mdl-35891618

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants of concern have been emerging. However, knowledge of temporal and spatial dynamics of SARS-CoV-2 is limited. This study characterized SARS-CoV-2 evolution in immunosuppressed patients with long-term SARS-CoV-2 shedding for 73-250 days, without specific treatment. We conducted whole-genome sequencing of 27 serial samples, including 26 serial samples collected from various anatomic sites of two patients and the first positive sample from patient 2's mother. We analysed the intrahost temporal dynamics and genomic diversity of the viral population within different sample types. Intrahost variants emerging during infection showed diversity between individual hosts. Remarkably, N501Y, P681R, and E484K, key substitutions within spike protein, emerged in vivo during infection and became the dominant population. P681R, which had not yet been detected in the publicly available genome in Korea, appeared within patient 1 during infection. Mutually exclusive substitutions at residues R346 (R346S and R346I) and E484 (E484K and E484A) of spike protein and continuous turnover of these substitutions occurred. Unique genetic changes were observed in urine samples. A household transmission from patient 2 to his mother, at least 38 days after the diagnosis, was characterized. Viruses may differently mutate and adjust to the host selective pressure, which could enable the virus to replicate efficiently for fitness in each host. Intrahost variants could be candidate variants likely to spread to the population eventually. Our findings may provide new insights into the dynamics of SARS-CoV-2 in response to interactions between the virus and host.


Subject(s)
COVID-19 , Immunocompromised Host , SARS-CoV-2 , Virus Shedding , COVID-19/transmission , Humans , Mutation , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Whole Genome Sequencing
6.
BMC Genomics ; 23(1): 497, 2022 Jul 08.
Article in English | MEDLINE | ID: mdl-35804296

ABSTRACT

BACKGROUND: Emerging infectious disease-causing RNA viruses, such as the SARS-CoV-2 and Ebola viruses, are thought to rely on bats as natural reservoir hosts. Since these zoonotic viruses pose a great threat to humans, it is important to characterize the bat genome from multiple perspectives. Unsupervised machine learning methods for extracting novel information from big sequence data without prior knowledge or particular models are highly desirable for obtaining unexpected insights. We previously established a batch-learning self-organizing map (BLSOM) of the oligonucleotide composition that reveals novel genome characteristics from big sequence data. RESULTS: In this study, using the oligonucleotide BLSOM, we conducted a comparative genomic study of humans and six bat species. BLSOM is an explainable-type machine learning algorithm that reveals the diagnostic oligonucleotides contributing to sequence clustering (self-organization). When unsupervised machine learning reveals unexpected and/or characteristic features, these features can be studied in more detail via the much simpler and more direct standard distribution map method. Based on this combined strategy, we identified the Mb-level enrichment of CG dinucleotide (Mb-level CpG islands) around the termini of bat long-scaffold sequences. In addition, a class of CG-containing oligonucleotides were enriched in the centromeric and pericentromeric regions of human chromosomes. Oligonucleotides longer than tetranucleotides often represent binding motifs for a wide variety of proteins (e.g., transcription factor binding sequences (TFBSs)). By analyzing the penta- and hexanucleotide composition, we observed the evident enrichment of a wide range of hexanucleotide TFBSs in centromeric and pericentromeric heterochromatin regions on all human chromosomes. CONCLUSION: Function of transcription factors (TFs) beyond their known regulation of gene expression (e.g., TF-mediated looping interactions between two different genomic regions) has received wide attention. The Mb-level TFBS and CpG islands are thought to be involved in the large-scale nuclear organization, such as centromere and telomere clustering. TFBSs, which are enriched in centromeric and pericentromeric heterochromatin regions, are thought to play an important role in the formation of nuclear 3D structures. Our machine learning-based analysis will help us to understand the differential features of nuclear 3D structures in the human and bat genomes.


Subject(s)
COVID-19 , Chiroptera/genetics , Genome, Human/genetics , SARS-CoV-2/physiology , Animals , COVID-19/transmission , Chiroptera/virology , CpG Islands , Genomics/methods , Heterochromatin/chemistry , Heterochromatin/genetics , Humans , Molecular Conformation , Oligonucleotides/chemistry , Unsupervised Machine Learning
7.
Sci Rep ; 12(1): 12094, 2022 Jul 15.
Article in English | MEDLINE | ID: mdl-35840592

ABSTRACT

The emergence of a novel pathogen in a susceptible population can cause rapid spread of infection. High prevalence of SARS-CoV-2 infection in white-tailed deer (Odocoileus virginianus) has been reported in multiple locations, likely resulting from several human-to-deer spillover events followed by deer-to-deer transmission. Knowledge of the risk and direction of SARS-CoV-2 transmission between humans and potential reservoir hosts is essential for effective disease control and prioritisation of interventions. Using genomic data, we reconstruct the transmission history of SARS-CoV-2 in humans and deer, estimate the case finding rate and attempt to infer relative rates of transmission between species. We found no evidence of direct or indirect transmission from deer to human. However, with an estimated case finding rate of only 4.2%, spillback to humans cannot be ruled out. The extensive transmission of SARS-CoV-2 within deer populations and the large number of unsampled cases highlights the need for active surveillance at the human-animal interface.


Subject(s)
COVID-19 , Deer , SARS-CoV-2 , Viral Zoonoses , Animals , COVID-19/epidemiology , COVID-19/prevention & control , COVID-19/transmission , COVID-19/veterinary , Deer/virology , Environmental Monitoring , Humans , Risk Assessment , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Viral Zoonoses/epidemiology , Viral Zoonoses/transmission , Viral Zoonoses/virology
9.
Sci Rep ; 12(1): 12794, 2022 Jul 27.
Article in English | MEDLINE | ID: mdl-35896583

ABSTRACT

There is an ongoing debate on the implementation of the COVID-19 passport throughout Europe. We sought to build and test a feasible prevention strategy to ensure low SARS-CoV transmission risk in public events. We conducted a non-randomised controlled study. The intervention group obtained a confidential digital certificate of very low capacity for transmitting SARS-CoV-2 and attended socio-cultural events in Girona (Spain) between 1 April and 21 May 2021. The primary care services and a network of pharmacies cooperated in providing the certification. A group of non-attendees was randomly selected from pseudonymised health records as controls. We estimated the incidences of SARS-CoV-2 infection and recorded the challenges in the process. Follow-up was complete for 1351 participants, who were matched with 4050 controls. Mean age of the study population was 31.1 years, and 53% of participants were women. Incidence rates of SARS-CoV infection at 14 days in the group of attendees and non-attendees were 15.9 and 17.7 per 100,000 person-days, respectively; the difference between incidences was - 1.8 (95% CI - 22.8, 19.3). Implementation problems were minor, and 89.2% of respondents to a survey were satisfied with the process. The incidence rate of SARS-CoV-2 infection was not different in the intervention and control groups. These results are in favour of establishing a COVID-19 certificate to attend public events, and connote feasibility of implementation at a population level.


Subject(s)
COVID-19/prevention & control , COVID-19/transmission , SARS-CoV-2 , Adult , COVID-19/epidemiology , Female , Humans , Male , Risk Factors , Spain/epidemiology , Time Factors , Treatment Outcome
10.
Viruses ; 14(7)2022 07 19.
Article in English | MEDLINE | ID: mdl-35891545

ABSTRACT

Viruses from the Coronaviridae family have been reported to infect a large range of hosts, including humans. The latest human-infecting coronavirus, SARS-CoV-2, turned into a pandemic and subtypes with different transmissibility have appeared since then. The SARS-CoV-2 Spike (S) protein interacts with the angiotensin-converting enzyme 2 (ACE2) host receptor, and thus, in silico models, based on the structural features of the SARS-CoV-2 S protein-ACE2 receptor complex, as well as ACE2 amino acid patterns, may be used to predict the within- and between-species transmissibility of SARS-CoV-2 subtypes. Here, it is shown that at the beginning of the pandemic, the SARS-CoV-2 S protein was, as expected for a virus that just jumped the species barrier, ill-adapted to the human ACE2 receptor, and that the replacement of one SARS-CoV-2 variant by another is partially due to a better fitting of the S protein-human ACE2 complex. Moreover, it is shown that mutations that are predicted to lead to a better fit have increased in the population due to positive selection. It is also shown that the number of ACE2-interfacing residues is positively correlated with the transmissibility rate of SARS-CoV-2 variants. Finally, it is shown that the number of species that are susceptible to infection by SARS-CoV-2, and that could be a reservoir for this virus, is likely higher than previously thought.


Subject(s)
COVID-19 , SARS-CoV-2 , Angiotensin-Converting Enzyme 2 , Animals , COVID-19/transmission , Humans , Protein Binding , Receptors, Virus/metabolism , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/metabolism
11.
Multimedia | Multimedia Resources | ID: multimedia-9729

ABSTRACT

O vídeo explica como um padrão matemático é aplicado durante uma epidemia. O aplicativo FioLibras é um projeto do Instituto de Comunicação e Informação Científica e Tecnológica em Saúde da Fundação Oswaldo Cruz (Icict/Fiocruz), em parceria com o Núcleo de Estudos em Diversidade e Inclusão de Surdos da Universidade Federal Fluminense (Nuedis/UFF), e conta com financiamento do Fundo de Inovação da Fiocruz e do Ministério da Saúde, por meio do Programa Fiocruz de Fomento à Inovação (Inova Fiocruz).


Subject(s)
COVID-19/epidemiology , COVID-19/transmission , Coronavirus Infections , Information Dissemination , Sign Language , e-Accessibility
12.
Multimedia | Multimedia Resources | ID: multimedia-9720

ABSTRACT

O vídeo explica que o distanciamento social se trata de uma medida preventiva para diminuir o contato de pessoa a pessoa, com o objetivo de diminuir ou interromper a disseminação de uma doença. O aplicativo FioLibras é um projeto do Instituto de Comunicação e Informação Científica e Tecnológica em Saúde da Fundação Oswaldo Cruz (Icict/Fiocruz), em parceria com o Núcleo de Estudos em Diversidade e Inclusão de Surdos da Universidade Federal Fluminense (Nuedis/UFF), e conta com financiamento do Fundo de Inovação da Fiocruz e do Ministério da Saúde, por meio do Programa Fiocruz de Fomento à Inovação (Inova Fiocruz).


Subject(s)
Physical Distancing , COVID-19/transmission , COVID-19/prevention & control , Information Dissemination , Sign Language , e-Accessibility
13.
Indoor Air ; 32(6): e13064, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35762243

ABSTRACT

The exhalation of aerosols during musical performances or rehearsals posed a risk of airborne virus transmission in the COVID-19 pandemic. Previous research studied aerosol plumes by only focusing on one risk factor, either the source strength or convective transport capability. Furthermore, the source strength was characterized by the aerosol concentration and ignored the airflow rate needed for risk analysis in actual musical performances. This study characterizes aerosol plumes that account for both the source strength and convective transport capability by conducting experiments with 18 human subjects. The source strength was characterized by the source aerosol emission rate, defined as the source aerosol concentration multiplied by the source airflow rate (brass 383 particle/s, singing 408 particle/s, and woodwind 480 particle/s). The convective transport capability was characterized by the plume influence distance, defined as the sum of the horizontal jet length and horizontal instrument length (brass 0.6 m, singing 0.6 m and woodwind 0.8 m). Results indicate that woodwind instruments produced the highest risk with approximately 20% higher source aerosol emission rates and 30% higher plume influence distances compared with the average of the same risk indicators for singing and brass instruments. Interestingly, the clarinet performance produced moderate source aerosol concentrations at the instrument's bell, but had the highest source aerosol emission rates due to high source airflow rates. Flute performance generated plumes with the lowest source aerosol emission rates but the highest plume influence distances due to the highest source airflow rate. Notably, these comprehensive results show that the source airflow is a critical component of the risk of airborne disease transmission. The effectiveness of masking and bell covering in reducing aerosol transmission is due to the mitigation of both source aerosol concentrations and plume influence distances. This study also found a musician who generated approximately five times more source aerosol concentrations than those of the other musicians who played the same instrument. Despite voice and brass instruments producing measurably lower average risk, it is possible to have an individual musician produce aerosol plumes with high source strength, resulting in enhanced transmission risk; however, our sample size was too small to make generalizable conclusions regarding the broad musician population.


Subject(s)
Air Pollution, Indoor , COVID-19 , Respiratory Aerosols and Droplets , Singing , Aerosols/analysis , Air Pollution, Indoor/analysis , COVID-19/transmission , Humans , Music , Pandemics , Respiratory Aerosols and Droplets/virology
14.
Proc Natl Acad Sci U S A ; 119(24): e2202069119, 2022 06 14.
Article in English | MEDLINE | ID: mdl-35679343

ABSTRACT

Current vaccines have greatly diminished the severity of the COVID-19 pandemic, even though they do not entirely prevent infection and transmission, likely due to insufficient immunity in the upper respiratory tract. Here, we compare intramuscular and intranasal administration of a live, replication-deficient modified vaccinia virus Ankara (MVA)-based Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) spike (S) vaccine to raise protective immune responses in the K18-hACE2 mouse model. Using a recombinant MVA expressing firefly luciferase for tracking, live imaging revealed luminescence of the respiratory tract of mice within 6 h and persisting for 3 d following intranasal inoculation, whereas luminescence remained at the site of intramuscular vaccination. Intramuscular vaccination induced S-binding-Immunoglobulin G (IgG) and neutralizing antibodies in the lungs, whereas intranasal vaccination also induced Immunoglobulin A (IgA) and higher levels of antigen-specific CD3+CD8+IFN-γ+ T cells. Similarly, IgG and neutralizing antibodies were present in the blood of mice immunized intranasally and intramuscularly, but IgA was detected only after intranasal inoculation. Intranasal boosting increased IgA after intranasal or intramuscular priming. While intramuscular vaccination prevented morbidity and cleared SARS-CoV-2 from the respiratory tract within several days after challenge, intranasal vaccination was more effective as neither infectious virus nor viral messenger (m)RNAs were detected in the nasal turbinates or lungs as early as 2 d after challenge, indicating prevention or rapid elimination of SARS-CoV-2 infection. Additionally, we determined that neutralizing antibody persisted for more than 6 mo and that serum induced to the Wuhan S protein neutralized pseudoviruses expressing the S proteins of variants, although with less potency, particularly for Beta and Omicron.


Subject(s)
COVID-19 Vaccines , COVID-19 , Immunoglobulin A , Respiratory System , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccinia virus , Administration, Intranasal , Angiotensin-Converting Enzyme 2/genetics , Animals , Antibodies, Neutralizing/blood , Antibodies, Viral/blood , COVID-19/prevention & control , COVID-19/transmission , COVID-19 Vaccines/administration & dosage , COVID-19 Vaccines/immunology , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Mice , Mice, Transgenic , Respiratory System/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Vaccination/methods , Vaccinia virus/genetics , Vaccinia virus/immunology
15.
Emerg Infect Dis ; 28(8)2022 Aug.
Article in English | MEDLINE | ID: mdl-35710464

ABSTRACT

Household transmission is a primary source of SARS-CoV-2 spread. We used COVID-19 epidemiologic investigation data and viral genome analysis data collected in the city of Kyoto, Japan, during January 2020-June 2021 to evaluate the effects of different settings and viral strains on SARS-CoV-2 transmission. Epidemiologic investigations of 5,061 COVID-19 cases found that the most common category for close contact was within households (35.3%); this category also had the highest reverse transcription PCR positivity. The prevalent viral lineage shifted from B.1.1.214 in the third wave to the Alpha variant in the fourth wave. The proportion of secondary cases associated with households also increased from the third to fourth waves (27% vs. 29%). Among 564 contacts from 206 households, Alpha variant was significantly associated with household transmission (odds ratio 1.52, 95% CI 1.06-2.18) compared with B.1.1.214. Public health interventions targeting household contacts and specific variants could help control SARS-CoV-2 transmission.


Subject(s)
COVID-19 , SARS-CoV-2 , COVID-19/epidemiology , COVID-19/transmission , Contact Tracing , Humans , Japan/epidemiology , SARS-CoV-2/genetics
16.
Goiânia; SES-GO; 09 jun. 2022. 1-3 p.
Non-conventional in Portuguese | Coleciona SUS, CONASS, SES-GO | ID: biblio-1379419

ABSTRACT

Considerando a situação epidemiológica do estado de Goiás que evidencia acréscimo significativo na média móvel de casos, considerando também o aumento da taxa de positividade de 19% para 41,5%, nos meses de abril e maio de 2022 respectivamente e o aumento de hospitalizações por SRAG, recomenda-se a utilização de máscaras de proteção respiratória em grupos mais vulneráveis e lugares com maior chance de contaminação, a ampliação da vacinação em crianças de 5 a 11 anos e a ampliação de testagem de detecção de SARS- CoV-2 na rede pública


Considering the epidemiological situation of the state of Goiás, which shows a significant increase in the moving average of cases, also considering the increase in the positivity rate from 19% to 41.5%, in April and May 2022 respectively, and the increase in hospitalizations for SARS, it is recommended the use of respiratory protection masks in more vulnerable groups and places with greater chance of contamination, the expansion of vaccination in children aged 5 to 11 years and the expansion of SARS-CoV-2 detection testing in the network public


Subject(s)
Humans , COVID-19/prevention & control , SARS-CoV-2 , COVID-19/transmission
17.
Proc Natl Acad Sci U S A ; 119(27): e2200109119, 2022 Jul 05.
Article in English | MEDLINE | ID: mdl-35763573

ABSTRACT

Understanding the factors that influence the airborne survival of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosols is important for identifying routes of transmission and the value of various mitigation strategies for preventing transmission. We present measurements of the stability of SARS-CoV-2 in aerosol droplets (∼5 to 10 µm equilibrated radius) over timescales spanning 5 s to 20 min using an instrument to probe survival in a small population of droplets (typically 5 to 10) containing ∼1 virus/droplet. Measurements of airborne infectivity change are coupled with a detailed physicochemical analysis of the airborne droplets containing the virus. A decrease in infectivity to ∼10% of the starting value was observable for SARS-CoV-2 over 20 min, with a large proportion of the loss occurring within the first 5 min after aerosolization. The initial rate of infectivity loss was found to correlate with physical transformation of the equilibrating droplet; salts within the droplets crystallize at relative humidities (RHs) below 50%, leading to a near-instant loss of infectivity in 50 to 60% of the virus. However, at 90% RH, the droplet remains homogenous and aqueous, and the viral stability is sustained for the first 2 min, beyond which it decays to only 10% remaining infectious after 10 min. The loss of infectivity at high RH is consistent with an elevation in the pH of the droplets, caused by volatilization of CO2 from bicarbonate buffer within the droplet. Four different variants of SARS-CoV-2 were compared and found to have a similar degree of airborne stability at both high and low RH.


Subject(s)
Aerosolized Particles and Droplets , COVID-19 , SARS-CoV-2 , Aerosolized Particles and Droplets/chemistry , Aerosolized Particles and Droplets/isolation & purification , COVID-19/transmission , Humans , Humidity , Hydrogen-Ion Concentration , SARS-CoV-2/isolation & purification , SARS-CoV-2/pathogenicity
18.
Proc Natl Acad Sci U S A ; 119(26): e2112182119, 2022 06 28.
Article in English | MEDLINE | ID: mdl-35696558

ABSTRACT

Detailed characterization of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission across different settings can help design less disruptive interventions. We used real-time, privacy-enhanced mobility data in the New York City, NY and Seattle, WA metropolitan areas to build a detailed agent-based model of SARS-CoV-2 infection to estimate the where, when, and magnitude of transmission events during the pandemic's first wave. We estimate that only 18% of individuals produce most infections (80%), with about 10% of events that can be considered superspreading events (SSEs). Although mass gatherings present an important risk for SSEs, we estimate that the bulk of transmission occurred in smaller events in settings like workplaces, grocery stores, or food venues. The places most important for transmission change during the pandemic and are different across cities, signaling the large underlying behavioral component underneath them. Our modeling complements case studies and epidemiological data and indicates that real-time tracking of transmission events could help evaluate and define targeted mitigation policies.


Subject(s)
COVID-19 , Contact Tracing , SARS-CoV-2 , COVID-19/transmission , Humans , New York City/epidemiology , Pandemics , Population Dynamics , Time Factors , Washington/epidemiology
19.
Proc Natl Acad Sci U S A ; 119(26): e2203086119, 2022 06 28.
Article in English | MEDLINE | ID: mdl-35727979

ABSTRACT

Accurate measurements of the size and quantity of aerosols generated by various human activities in different environments are required for efficacious mitigation strategies and accurate modeling of respiratory disease transmission. Previous studies of speech droplets, using standard aerosol instrumentation, reported very few particles larger than 5 µm. This starkly contrasts with the abundance of such particles seen in both historical slide deposition measurements and more recent light scattering observations. We have reconciled this discrepancy by developing an alternative experimental approach that addresses complications arising from nucleated condensation. Measurements reveal that a large volume fraction of speech-generated aerosol has diameters in the 5- to 20-µm range, making them sufficiently small to remain airborne for minutes, not hours. This coarse aerosol is too large to penetrate the lower respiratory tract directly, and its relevance to disease transmission is consistent with the vast majority of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections initiating in the upper respiratory tract. Our measurements suggest that in the absence of symptoms such as coughing or sneezing, the importance of speech-generated aerosol in the transmission of respiratory diseases is far greater than generally recognized.


Subject(s)
Respiratory Aerosols and Droplets , Respiratory Tract Infections , Speech , COVID-19/transmission , Humans , Particle Size , Respiratory Tract Infections/transmission , SARS-CoV-2 , Time Factors
20.
Science ; 377(6604): 428-433, 2022 07 22.
Article in English | MEDLINE | ID: mdl-35737809

ABSTRACT

The in vivo pathogenicity, transmissibility, and fitness of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant are not well understood. We compared these virological attributes of this new variant of concern (VOC) with those of the Delta (B.1.617.2) variant in a Syrian hamster model of COVID-19. Omicron-infected hamsters lost significantly less body weight and exhibited reduced clinical scores, respiratory tract viral burdens, cytokine and chemokine dysregulation, and lung damage than Delta-infected hamsters. Both variants were highly transmissible through contact transmission. In noncontact transmission studies Omicron demonstrated similar or higher transmissibility than Delta. Delta outcompeted Omicron without selection pressure, but this scenario changed once immune selection pressure with neutralizing antibodies-active against Delta but poorly active against Omicron-was introduced. Next-generation vaccines and antivirals effective against this new VOC are therefore urgently needed.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , COVID-19/transmission , Disease Models, Animal , Mesocricetus , SARS-CoV-2/pathogenicity , Virulence
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