In mid-December, the number of confirmed infections by the new variant\u2014identified as VUI 202012\/01 (Variant Under Investigation, year 2020, month 12, variant 01) and belonging to lineage B.1.1.7\u2014increased every day in the UK. The strain has already been identified in Australia, Denmark, and the Netherlands.<\/p>\n
\n– Approval strategy<\/a>
\n– Distribution challenges<\/a>
\n– The era of genetic vaccines<\/a>
\n<\/div>\n
According to the ECDC report, the new variant has 29 mutations from the original virus identified in Wuhan, China, nine of which affect the spike protein used by the virus to infiltrate human cells. \u201cOne of the mutations is a deletion [where a piece of the gene is lost] at position 69-70 of the spike protein,<\/em>\u201d Said Faria. “In the lab, this mutation appears to result in an increased viral load, which may be associated with faster transmission.” The higher the viral load in a patient, the more of the virus they will exhale, increasing the likelihood that they will infect someone else.<\/p>\n According to virologist and president of the Brazilian Society of Virology Fernando Spilki, from Feevale University in Novo Hamburgo, Rio Grande do Sul, no specimens of SARS-CoV-2 whose genome has been fully sequenced in Brazil have belonged to lineage B.1.1.7. “We are actively searching,” he said, referring to a network of virologists instituted to monitor the evolution of the novel coronavirus. One of the mutations in the new variant, identified as N501Y, was present in a sequence analyzed by Brazilian researchers in April, but it appears to have since disappeared from the country.<\/p>\n Ole Jensen \/ Getty Images<\/span><\/a> Mink raised in captivity in European countries are related to SARS-CoV-2 mutationsOle Jensen \/ Getty Images<\/span><\/p><\/div>\n VUI 202012\/01 is not the first SARS-CoV-2 variant causing concern among scientists and authorities. In early November, the government of Denmark, the world’s largest producer of mink fur, decided to cull every mink in captivity because of mutations in the virus identified on fur farms.<\/p>\n Within a matter of weeks, 11 million of the country’s nearly 17 million mink had been euthanized. The Nordic country also banned mink breeding until the end of 2021. The move came after it was found that the novel coronavirus had jumped from infected farmers and workers to the minks, spread quickly among the animals without killing them, and then jumped back to humans with alterations to its genetic code.<\/p>\n Researchers in the country have identified at least 170 variants of coronavirus related to the minks. One variant in particular, known as cluster 5, drew particular attention due to having four mutations in the part of the genome that encodes the spike protein. According to the WHO, preliminary findings suggest that human antibodies are less adept at neutralizing viruses of this lineage.<\/p>\n So far, no change has been found in terms of SARS-Cov-2\u2019s virulence due to this or any other of the identified mutations, but scientists are wary of the possible consequences on the immune response conferred by vaccines. Most of the vaccines under development target the virus\u2019s spike protein.<\/p>\n \u201cIt is too early to know the potential implications of the mutations circulating in relation to the vaccines in production, which are based on sequences of the spike protein from the virus circulating a year ago,\u201d says Faria. \u201cAt the moment, the data show that the virus\u2019s relatively slow evolution will benefit these vaccines. There is also evidence that people have similar immune responses to infections by different variants. The clinical outcome depends more on demographic and socioeconomic factors, such as age, sex, comorbidities, and health care access.\u201d<\/p>\n Thousands of SARS-CoV-2 mutations have already been identified, but not all affect the genome. From the end of 2019, when the first infections were recorded, until December 2020, the novel coronavirus has accumulated about two fixed mutations per month, says the virologist. \u201cNew genetic variants emerge and spread in the viral population as a result of a complex combination of genetic drift [the evolutionary mechanism of genes], natural selection, epidemiological processes, and modes of transmission. Some of these variants thrive, becoming widespread in the population during the course the pandemic,\u201d he says. According to the scientist, the virus\u2019s evolution speed\u2014the rate at which new variants of SARS-CoV-2 emerge\u2014was estimated at about 30 fixed mutations of the genome per year.<\/p>\n While the terms “mutation” and “mutant virus” may sound scary to the general public, they are commonly used by virologists and biologists. Mutations are part of the evolutionary process of all organisms, including plants, animals, and microorganisms. \u201cViruses undergo mutations, just like every other living being,\u201d says Brazilian biomedical expert William Marciel de Souza, who is at the University of Oxford conducting postdoctoral research on genomic and metabolomic approaches to the study of Chikungunya disease. According to Faria, more than 800 strains of SARS-CoV-2 have been identified around the world. Of these, at least 40 have been detected in Brazil, but the number could be higher, since it is possible that other strains are circulating that have not yet been identified.<\/p>\n A mutation is any change in the genetic code, according to virologist Francisco Murilo Zerbini of the Federal University of Vi\u00e7osa (UFV) in Minas Gerais, president of the International Committee on Taxonomy of Viruses (ICTV), an organization formed by professionals who work with viral classification. In humans, most animals, plants, and microorganisms such as fungi and bacteria, the information needed to reproduce and function is stored in DNA molecules. Viruses are the only microorganisms that can also store genetic information in RNA molecules, which is the case with SARS-CoV-2. Any alteration to the base sequence of the genome, which usually occurs during replication, is called a mutation.<\/p>\n Of more than 800 strains of SARS-CoV-2 identified worldwide, at least 40 have been detected in Brazil<\/p><\/blockquote>\n But while human beings take years to reproduce, viruses replicate millions or billions of times per day. In the process, sequences of the nucleotides (the base chemical unit of genes) that compose their RNA or DNA can be altered. \u201cThis is completely random. Because viruses replicate so quickly and generate so many copies, they evolve very quickly, unlike us,\u201d explains Souza. Mutations can occur anywhere in the genome and may or may not be beneficial to the virus. According to Souza, new strains tend to become more infectious and less lethal\u2014the virus needs to replicate, and it needs the cells of a living host to do so.<\/p>\n The novel coronavirus is an RNA molecule, protected by a protein shell (capsid), which in turn is enclosed within a lipid envelope, derived from the host cell. It is part of the Coronaviridae family\u2014the envelope of which has a spike-shaped S protein, giving the virus its crown appearance\u2014and the Betacoronavirus <\/em>genus. Because it is an RNA virus, it is less stable and more likely to mutate than DNA viruses. The former generally have long genomes and molecules that correct errors in the genetic code during replication.<\/p>\n \u201cAn example of a DNA virus is herpes, which is very stable and can have up to 250,000 base pairs,\u201d says Souza. SARS-CoV-2, meanwhile, has 30,000 bases. Among all RNA viruses, the coronavirus has one of the longest genomes. “Most of the RNA viruses that cause disease in humans or animals have a shorter genome, such as Zika, Chikungunya, dengue, and yellow fever.” All have between 10,000 and 12,000 bases.<\/p>\n \u201cSARS-CoV-2 actually changes very little. Compared to other RNA viruses, it is monotonous,\u201d notes Spilki. \u201cWhen we talk about mutant strains, people probably think that one lineage has a completely different genome to another; that\u2019s not the case with the coronavirus. Of the nearly 30,000 nucleotides in its genome, we sometimes see four, five, or six different ones from one lineage to another. This is a virus with a very stable genome.\u201d According to Spilki, this is because SARS-CoV-2, despite being an RNA virus, has an enzyme that can correct errors when they occur.<\/p>\n The vast majority of mutations have a negative impact on viruses, says Zerbini. “They usually cause them to replicate less efficiently, and so with these harmful mutations, variants tend to disappear.” There are some, however, that have a positive impact\u2014and in such cases, the new variant often becomes predominant. So far, one of the most investigated new strains of the novel coronavirus is D614G. It emerged in China in January 2020, quickly spread to Europe and New York, and in March and April it became dominant worldwide, including in the Americas. Although it has not been linked to any increase in severity, some studies suggest that the virus with this mutation has a moderately faster transmission rate.<\/p>\n “Laboratory analyses indicate that cellular infectivity is higher in animals infected with the D614G variant,” said Brazilian microbiologist Fabr\u00edcia Ferreira do Nascimento, a researcher at Imperial College London. Infectivity is the ability of a pathogen to infect and multiply within a host. Nascimento coauthored an article published in the journal Cell<\/em> in November that described a study of more than 25,000 SARS-CoV-2 genome sequences, conducted in the UK, that analyzed the effects of the D614G mutation on the transmissibility and pathogenicity of the virus. “In the human population, infections with this variant were associated with a high viral load.”<\/p>\n In Brazil, says Spilki, the most prevalent strains of the novel coronavirus as of November were B.1.1.28 and B.1.1.33. Both carry the D614G mutation. \u201cThis is not just in Brazil, it\u2019s worldwide. They are the most predominant strains in most countries.\u201d Spilki heads a network of scientists set to begin large-scale genetic sequencing of the SARS-CoV-2 variants found in Brazil. \u201cThousands of virus genomes will be sequenced. We want to understand how the virus is transmitted.\u201d<\/p>\n Rede Corona-\u00f4mica BR, an initiative created by the Ministry of Science, Technology, and Innovations (MCTI), is composed of scientists from 12 institutions, including the University of Campinas (UNICAMP), S\u00e3o Paulo State University (UNESP), the Federal University of Rio de Janeiro (UFRJ), USP, and the Oswaldo Cruz Foundation (FIOCRUZ). \u201cOne of the network\u2019s goals is to detect mutations and to understand how the virus evolves and spreads, to identify epidemiological chains and how it moves from one location to another, whether in hospitals, within families, or in population centers,\u201d says Spilki.<\/p>\n The researchers highlight that when the virus jumps into a different species, it mutates until it finds a balance, adapting to its new environment. They are therefore concerned about the strains coming from mink in Denmark. For the experts, the Danish case and the lineage identified in Southeast England show the importance of robust surveillance, including the sequencing of virus samples and sharing of data between countries and scientists.<\/p>\n Project<\/strong> Scientific articles<\/strong>![\"\"](\"https:\/\/revistapesquisa.fapesp.br\/wp-content\/uploads\/2021\/03\/028-031_covid-mutacoes_299-1-1140.jpg\")
\nMulti-omic approaches to the study of chikungunya disease (No. 19\/24251-9<\/a>); Grant Mechanism<\/strong> Postdoctoral Fellowship; Supervisor<\/strong> Luiz Tadeu Moraes Figueiredo (USP); Beneficiary<\/strong> William Marciel de Souza; Investment<\/strong> R$341,618.72.<\/p>\n
\nVOLZ, E. et al.<\/em> Evaluating the effects of Sars-CoV-2 spike mutation D614G on transmissibility and pathogenicity<\/a>. Cell<\/strong>. Nov. 19, 2020.
\nKORBER, B. et al<\/em>. Tracking changes in Sars-CoV-2 Spike: evidence that D614G increases Infectivity of the Covid-19 virus<\/a>. Cell<\/strong>. Vol. 182, pp. 794\u201395. Aug. 20, 2020.
\nSOUZA, W. et al.<\/em> Epidemiological and clinical characteristics of the Covid-19 epidemic in Brazil<\/a>. Nature Human Behaviour<\/strong>. July 31, 2020.
\nVAN DORP, L. et al<\/em>. No evidence for increased transmissibility from recurrent mutations in SARS-CoV-2<\/a>. Nature Communications<\/strong>. Nov. 25, 2020.<\/p>\n","protected":false},"excerpt":{"rendered":"New strains of SARS-Cov-2, such as the one identified in the United Kingdom in December, could make the pathogen more transmissible and virulent","protected":false},"author":468,"featured_media":387340,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"footnotes":""},"categories":[3674,159],"tags":[229,260],"coauthors":[778],"class_list":["post-386996","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-covid-19-en","category-science","tag-epidemiology","tag-public-health","keywords-coronavirus-en","keywords-covid-19-en","keywords-sars-cov-2-en","keywords-virology"],"acf":[],"_links":{"self":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/386996","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/users\/468"}],"replies":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/comments?post=386996"}],"version-history":[{"count":5,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/386996\/revisions"}],"predecessor-version":[{"id":389201,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/posts\/386996\/revisions\/389201"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media\/387340"}],"wp:attachment":[{"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/media?parent=386996"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/categories?post=386996"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/tags?post=386996"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/revistapesquisa.fapesp.br\/en\/wp-json\/wp\/v2\/coauthors?post=386996"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}