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N501Y
There are many variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes coronavirus disease 2019 (COVID-19). Some are believed, or have been stated, to be of particular importance due to their potential for increased transmissibility, increased virulence, or reduced effectiveness of vaccines against them. These variants contribute to the continuation of the COVID-19 pandemic. only the Omicron variant is designated as a circulating variant of concern by the World Health Organization. Overview The emergence of SARS-CoV-2 may have resulted from recombination events between a bat SARS-like coronavirus and a pangolin coronavirus through cross-species transmission. The earliest available SARS-CoV-2 viral genomes were collected from patients in December 2019, and Chinese researchers compared these early genomes with bat and pangolin coronavirus strains to estimate the ancestral human coronavirus type; the identified ancestral genome typ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2 Alpha Variant
The Alpha variant (B.1.1.7) was a SARS-CoV-2 variant of concern. It was estimated to be 40–80% more transmissible than the wild-type SARS-CoV-2 (with most estimates occupying the middle to higher end of this range). It was first detected in November 2020 from a sample taken in September in the United Kingdom, and began to spread quickly by mid-December, around the same time as infections surged. This increase is thought to be at least partly because of one or more mutations in the virus' spike protein. The variant was also notable for having more mutations than normally seen. By January 2021, more than half of all genomic sequencing of SARS-CoV-2 was carried out in the UK. This had given rise to questions as to how many other important variants were circulating around the world undetected. On 2 February 2021, Public Health England reported that they had detected " limited number of B.1.1.7 VOC-202012/01 genomes with E484K mutations", which they dubbed Variant of Conce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2 Beta Variant
The Beta variant, (B.1.351), was a variant of SARS-CoV-2, the virus that causes COVID-19. One of several SARS-CoV-2 variants initially believed to be of particular importance, it was first detected in the Nelson Mandela Bay metropolitan area of the Eastern Cape province of South Africa in October 2020, which was reported by the country's health department on 18 December 2020. Phylogeographic analysis suggests this variant emerged in the Nelson Mandela Bay area in July or August 2020. The World Health Organization labelled the variant as Beta variant, not to replace the scientific name but as a name for the public to commonly refer to. The WHO considers it to be a variant of concern no longer in circulation. Names The variant is also known as the ''South African variant''. Mutations File:SARS-CoV-2 Beta variant.svg, Amino acid mutations of SARS-CoV-2 Beta variant plotted on a genome map of SARS-CoV-2 with a focus on Spike. There are three mutations of particular in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2 Gamma Variant
The Gamma variant (P.1) was one of the variants of SARS-CoV-2, the virus that causes COVID-19. This variant of SARS-CoV-2 has been named lineage P.1 and has 17 amino acid substitutions, ten of which in its spike protein, including these three designated to be of particular concern: N501Y, E484K and K417T. This variant of SARS-CoV-2 was first detected by the National Institute of Infectious Diseases (NIID) of Japan, on 6 January 2021 in four people who had arrived in Tokyo having visited Amazonas, Brazil, four days earlier. It was subsequently declared to be in circulation in Brazil. Under the simplified naming scheme proposed by the World Health Organization, P.1 has been labeled Gamma variant, and is currently considered a variant of concern. Gamma caused widespread infection in early 2021 in the city of Manaus, the capital of Amazonas, although the city had already experienced widespread infection in May 2020, with a study indicating high seroprevalence of antibodies ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severe Acute Respiratory Syndrome Coronavirus 2
Severe acute respiratory syndrome coronavirus 2 (SARS‑CoV‑2) is a strain of coronavirus that causes COVID-19 (coronavirus disease 2019), the respiratory illness responsible for the ongoing COVID-19 pandemic. The virus previously had a provisional name, 2019 novel coronavirus (2019-nCoV), and has also been called the human coronavirus 2019 (HCoV-19 or hCoV-19). First identified in the city of Wuhan, Hubei, China, the World Health Organization declared the outbreak a public health emergency of international concern on January 30, 2020, and a pandemic on March 11, 2020. SARS‑CoV‑2 is a positive-sense single-stranded RNA virus that is contagious in humans. SARS‑CoV‑2 is a virus of the species ''severe acute respiratory syndrome–related coronavirus'' (SARSr-CoV), related to the SARS-CoV-1 virus that caused the 2002–2004 SARS outbreak. Despite its close relation to SARS-CoV-1, its closest known relatives, with which it forms a sister group, are the derived SAR ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variant Of Concern
The term variant of concern (VOC) for SARS-CoV-2, which causes COVID-19, is a category used for variants of the virus where mutations in their spike protein receptor binding domain (RBD) substantially increase binding affinity (e.g., N501Y) in RBD-hACE2 complex (genetic data), while also being linked to rapid spread in human populations (epidemiological data). Before this, an emerging variant may have been labeled a variant of interest, or in some countries a variant under investigation. During or after fuller assessment as a variant of concern the variant is typically assigned to a lineage in the PANGOLIN nomenclature system and to clades in the Nextstrain and GISAID systems. During the COVID-19 pandemic, the SARS-CoV-2 virus has been observed to mutate, with certain combinations of specific point mutations proving to be more concerning than others. This was principally for reasons of transmissibility and virulence, and also with regard to the possible emergence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SARS-CoV-2 Omicron Variant
Omicron (B.1.1.529) is a variant of SARS-CoV-2 first reported to the World Health Organization (WHO) by the Network for Genomics Surveillance in South Africa on 24 November 2021. It was first detected in Botswana and has spread to become the predominant variant in circulation around the world. Following the original BA.1 variant, several subvariants of Omicron have emerged: BA.2, BA.3, BA.4, and BA.5. Since October 2022, two subvariants of BA.5 named BQ.1 and BQ.1.1 have spread rapidly. Three doses of a COVID-19 vaccine provide protection against severe disease and hospitalisation caused by BA.1 and BA.2. The immunity effects of BA.2 are similar to those of BA.1. For three-dose vaccinated individuals, the BA.4 and BA.5 variants are more infectious than previous subvariants, making it likely, , for a new peak in COVID-19 infections to occur. __TOC__ Classification On 26 November, the WHO's Technical Advisory Group on SARS-CoV-2 Virus Evolution declared PANGO linea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Variants Of Concern
The term variant of concern (VOC) for SARS-CoV-2, which causes COVID-19, is a category used for variants of the virus where mutations in their spike protein receptor binding domain (RBD) substantially increase binding affinity (e.g., N501Y) in RBD-hACE2 complex (genetic data), while also being linked to rapid spread in human populations (epidemiological data). Before this, an emerging variant may have been labeled a variant of interest, or in some countries a variant under investigation. During or after fuller assessment as a variant of concern the variant is typically assigned to a lineage in the PANGOLIN nomenclature system and to clades in the Nextstrain and GISAID systems. During the COVID-19 pandemic, the SARS-CoV-2 virus has been observed to mutate, with certain combinations of specific point mutations proving to be more concerning than others. This was principally for reasons of transmissibility and virulence, and also with regard to the possible emergence of esc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic Assignment Of Named Global Outbreak Lineages
The Phylogenetic Assignment of Named Global Outbreak Lineages (PANGOLIN) is a software tool developed by Dr. Áine O'Toole and members of the Andrew Rambaut laboratory, with an associated web application developed by the Centre for Genomic Pathogen Surveillance in South Cambridgeshire. Its purpose is to implement a dynamic nomenclature (known as the PANGO nomenclature) to classify genetic lineages for SARS-CoV-2, the virus that causes COVID-19. A user with a full genome sequence of a sample of SARS-CoV-2 can use the tool to submit that sequence, which is then compared with other genome sequences, and assigned the most likely lineage (PANGO lineage). Single or multiple runs are possible, and the tool can return further information regarding the known history of the assigned lineage. Additionally, it interfaces with Microreact, to show a time sequence of the location of reports of sequenced samples of the same lineage. This latter feature draws on publicly available genomes obtaine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lineage (genetic)
A genetic lineage, also known as genetic pedigree, is a series of mutations which connect an ancestral genetic type (allele, haplotype, or haplogroup) to derivative type. In cases where the genetic tree is very bushy the order of mutations in the lineage is mostly known, examples are the order of mutations between E1b1b and E1b1b1a1a for the human Y-chromosomesal L0 or L1 nodes. A genetic lineage can be contrasted with an evolutionary lineage in that a genetic lineage applies to a locus. An example of the difference is that an ancient African ape evolved into the gorilla-chimpanzee-human ancestor, which further evolved into the chimpanzee-human ancestor and then to humans. While most human lineages coalesce with chimpanzee lineages, which then converge with gorilla lineages, a few human lineages coalesce with gorilla lineages and then converge with chimpanzee lineages (or chimpanzee lineages that coalesce with gorilla lineages and then converge with human lineages). This occu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nextstrain
Nextstrain is a collaboration between researchers in Seattle, United States and Basel, Switzerland which provides a collection of open-source tools for visualising the genetics behind the spread of viral outbreaks. Its aim is to support public health measures and surveillance by facilitating understanding of the spread and evolution of pathogens. The Nextstrain platform was begun in 2015. Code developed by Nextstrain is made publicly available, via, for example github.com and its data is available and viewable in accessible form via the pages at the website. Applications According to their website, the Nextstrain team maintains an up-to-date genomic analysis of each of the following pathogens: * Avian influenza * Dengue * Enterovirus D68 * Measles * Mumps * SARS-CoV-2 * Seasonal influenza * Tuberculosis * West Nile virus * West African Ebola 2013-16 * Zika * Monkeypox virus Covid-19 pandemic Nextstrain and its results have been widely quoted during the COVID-19 pandemic. Awar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clade
A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, the equivalent Latin term ''cladus'' (plural ''cladi'') is often used in taxonomical literature. The common ancestor may be an individual, a population, or a species (extinct or extant). Clades are nested, one in another, as each branch in turn splits into smaller branches. These splits reflect evolutionary history as populations diverged and evolved independently. Clades are termed monophyletic (Greek: "one clan") groups. Over the last few decades, the cladistic approach has revolutionized biological classification and revealed surprising evolutionary relationships among organisms. Increasingly, taxonomists try to avoid naming taxa that are not clades; that is, taxa that are not monophyletic. Some of the relationships between org ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Disease Outbreak
In epidemiology, an outbreak is a sudden increase in occurrences of a disease when cases are in excess of normal expectancy for the location or season. It may affect a small and localized group or impact upon thousands of people across an entire continent. The number of cases varies according to the disease-causing agent, and the size and type of previous and existing exposure to the agent. Outbreaks include many epidemics, which term is normally only for infectious diseases, as well as diseases with an environmental origin, such as a water or foodborne disease. They may affect a region in a country or a group of countries. Pandemics are near-global disease outbreaks when multiple and various countries around the Earth are soon infected. Definition The terms "outbreak" and "epidemic" have often been used interchangeably. Researchers Manfred S. Green and colleagues propose that the latter term be restricted to larger events, pointing out that '' Chambers Concise Dictionary'' and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
