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Discussione: Nuovo CoronaVirus

  1. #1941
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    Coronavirus: Francia, caso re-infezione grave con variante sudafricana


    Parigi, 12 feb. (Adnkronos) - Una prima re-infezione grave con la variante sudafricana del coronavirus è stata segnalata in Francia. Il caso è descritto in uno studio degli ospedali di Parigi (Ap-Hp) e pubblicato dalla rivista Clinical Infectious Diseases, riferisce le Figaro.

    Il paziente, un uomo di 58 anni con problemi di asma, si era ammalato una prima volta di covid-19 in settembre, con febbre e difficoltà respiratorie moderate. I sintomi erano però scomparsi in pochi giorni e l'uomo era risultato negativo a due test in dicembre. In gennaio è stato però ricoverato nel reparto urgenze dell'ospedale Louis-Mourier di Colmbes, vicino Parigi. E' risultato nuovamente positivo al test e la sequenza genetica ha chiarito che si tratta della variante sudafricana. Sette giorni più tardi il suo stato si è aggravato fino a diventare critico e il paziente è stato intubato e sottoposto a ventilazione artificiale. Al momento del ricovero, il test sierologico aveva evidenziato la presenza di anticorpi dovuta alla precedente infezione.

    Altri casi di re-infezione del covid con una variante diversa della malattia, scrive Le Figaro, sono già stati descritti nelle riviste scientifiche, ma spesso il secondo episodio era più leggero del primo. Secondo lo studio francese, si tratta "a nostra conoscenza, della prima descrizione di una re-infezione con la variante sudafricana che provoca un covid-19 grave, quattro mesi dopo una prima infezione moderata".
    https://www.liberoquotidiano.it/news...dafricana.html.
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

  2. #1942
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    https://www.ansa.it/sito/notizie/pol...bd2943171.html.

    L'Iss: 'Preoccupano le varianti, rafforzare le misure'
    'Impatto rilevante senza misure adeguate'


    Considerata la circolazione nelle diverse aree del paese "si raccomanda di intervenire al fine di contenere e rallentare la diffusione della variante VOC 202012/0, rafforzando/innalzando le misure in tutto il paese e modulandole ulteriormente laddove più elevata è la circolazione, inibendo in ogni caso ulteriori rilasci delle attuali misure in atto". E' quanto afferma l'Istituto superiore di sanità nello studio di prevalenza della variante VOC 202012/01 (Regno Unito) in Italia, relativo alla indagine svolta lo scorso 4-5 febbraio.

    "Nel contesto italiano, in cui la vaccinazione delle categorie di popolazione più fragile sta procedendo rapidamente ma non ha ancora raggiunto coperture sufficienti, la diffusione di varianti a maggiore trasmissibilità può avere un impatto rilevante se non vengono adottate misure di mitigazione adeguata", sottolinea l'Istituto superiore di sanità nello studio di prevalenza della variante VOC 202012/01 (Regno Unito) in Italia relativo alla indagine svolta lo scorso 4-5 febbraio.

    A causa delle varianti il rischio associato a un'ulteriore diffusione del Covid nell'Ue è "attualmente valutato come alto-molto alto per la popolazione complessiva e molto alto per gli individui vulnerabili".
    Lo scrive l'Ecdc nella sua analisi del rischio aggiornata. I paesi dovrebbero accelerare le campagne di vaccinazione, raccomanda l'Agenzia, poiché le varianti hanno "maggiore trasmissibilità" e potrebbero "determinare una maggiore gravità della malattia", e "i vaccini con licenza esistenti" potrebbero essere "solo parzialmente o in gran parte meno efficaci".

    Per "contenere e rallentare" la diffusione delle varianti del Covid, "in analogia con le strategie adottate negli altri paesi europei", è necessaria una "rigorosa osservanza, rafforzamento e incremento delle misure di mitigazione del rischio sia in ambito nazionale che in specifici ambiti locali, evitando ulteriori misure di rilascio". E' l'indicazione che gli esperti del Comitato tecnico scientifico hanno dato venerdì scorso al termine della riunione in cui hanno analizzato gli ultimi dati epidemiologici e preso atto dello studio dell'Istituto superiore di sanità sulla diffusione delle varianti del virus in Italia.

    "L'incidenza dell'epidemia - hanno scritto nel verbale al termine della riunione i tecnici e gli scienziati - risulta nuovamente in crescita, con un impatto sostenuto sui sistemi sanitari". E l'incremento dell'incidenza dovuta alle varianti "potrebbe prefigurare scenari con un nuovo rapido aumento diffuso nel numero di casi nelle prossime settimane". Di qui, è la conclusione, la necessità della "rigorosa osservanza, rafforzamento e incremento" delle misure.

    Intanto è polemica dopo che Walter Ricciardi, consigliere del ministro della Salute Roberto Speranza, ha ipotizzato un lockdown stringente per contrastare la pandemia. 'Queste sono considerazioni che lascio alla politica. Se posso essere utile al Paese con i miei consigli, lo faccio a livello internazionale e lo faccio anche in Italia. Altrimenti, mi faccio da parte'. Lo afferma Walter Ricciardi, consigliere del ministro della Salute Roberto Speranza, a Rainews24, rispondendo alle polemiche e richieste di dimissioni da parte di alcuni.
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

  3. #1943
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    Spoiler:
    New Covid variant with potentially worrying mutations found in UK
    Researchers say 32 cases of B1525 in Britain, with other cases in countries including Denmark, US and Australia


    Another coronavirus variant with a potentially worrying set of mutations has been detected in the UK and should be targeted in surge testing, experts have said.

    The variant, known as B1525, is the subject of a report by researchers at the University of Edinburgh, who say it has been detected through genome sequencing in 10 countries including Denmark, the US and Australia, with 32 cases found in the UK so far. The earliest sequences were dated to December and cropped up in the UK and Nigeria.

    The team say the variant has similarities in its genome to the Kent variant, B117, and it contains a number of mutations that have worried researchers, including the E484K mutation to the spike protein – a protein found on the outside of the virus that plays an important role in helping the virus to enter cells.
    This E484K mutation is present in variants that emerged in South Africa and Brazil and is thought to help the virus evade neutralising antibodies.

    Dr Simon Clarke, an associate professor of cellular microbiology at the University of Reading, said that while it was unclear what effect many of the mutations may have on the ability of the coronavirus to establish an infection, or on the severity of disease, the presence of the E484K mutation was known in the South Africa variant to confer a degree of resistance to some vaccines.

    “We don’t yet know how well this [new] variant will spread, but if it is successful it can be presumed that immunity from any vaccine or previous infection will be blunted,” he said.

    Clarke added that the new variant should be included in efforts to boost testing to pick up variants of concern. “I think that until we know more about these variants, any variants which carry E484K should be subject to surge testing as it seems to confer resistance to immunity, however that is generated,” he said.

    Ravi Gupta, a professor of clinical microbiology at the University of Cambridge, agreed surge testing for the new variant was warranted, noting that as well as the E484K mutation it had another change “that likely helps it escape from our antibodies”.

    But Prof Jonathan Stoye, a group leader at the Francis Crick Institute, said that while the variant was clearly spreading, surge testing had problems, including that those most at risk of spreading Covid may not come forward, for example because they cannot afford financially to test positive.

    Stoye said it was not surprising that the new variant contained some familiar mutations. “The minute you start putting selection pressure on this virus, you start selecting particularly for things that give it the ability to escape immune responses, and I think that is what we are seeing here,” he said.

    But the discovery that several variants of concern share the same mutations means tweaks to the current Covid vaccines would be expected to offer protection against multiple new variants. “This [E484K] change seems to be the key change at the moment to allow escape, so that’s the one you put into the tweaked vaccine,” said Stoye.

    Dr Lucy van Dorp, of the Genetics Institute at University College London, said rapid detection of new variants was crucial. “One of the major advantages of genomic surveillance is to pick up lineages of potential concern early, while still at low frequency, to allow quick assessment and evaluation of their impact and prevalence in other regions of the world,” she said.

    Public Health England said: “PHE is monitoring data about emerging variants very closely and where necessary public health interventions are being undertaken, such as extra testing and enhanced contact tracing.

    “There is currently no evidence that this set of mutations causes more severe illness or increased transmissibility.”


    https://www.theguardian.com/world/20...rn-found-in-uk



    Una variante simile a quella brasiliana e sudafricana é stato isolato in UK.
    Ultima modifica di Blitz76; 17-02-2021 alle 02:34
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

  4. #1944
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    A laboratory study suggests that the South African variant of the coronavirus may reduce antibody protection from the Pfizer Inc/BioNTech SE vaccine by two-thirds, and it is not clear if the shot will be effective against the mutation, the companies said on Wednesday.

    The study found the vaccine was still able to neutralize the virus and there is not yet evidence from trials in people that the variant reduces vaccine protection, the companies said.

    Still, they are making investments and talking to regulators about developing an updated version of their mRNA vaccine or a booster shot, if needed.
    For the study, scientists from the companies and the University of Texas Medical Branch (UTMB) developed an engineered virus that contained the same mutations carried on the spike portion of the highly contagious coronavirus variant first discovered in South Africa, known as B.1.351. The spike, used by the virus to enter human cells, is the primary target of many COVID-19 vaccines.

    Researchers tested the engineered virus against blood taken from people who had been given the vaccine, and found a two- thirds reduction in the level of neutralizing antibodies compared with its effect on the most common version of the virus prevalent in U.S. trials.

    Their findings were published in the New England Journal of Medicine (NEJM).

    Because there is no established benchmark yet to determine what level of antibodies are needed to protect against the virus, it is unclear whether that two-thirds reduction will render the vaccine ineffective against the variant spreading around the world.

    However, UTMB professor and study co-author Pei-Yong Shi said he believes the Pfizer vaccine will likely be protective against the variant.

    "We don't know what the minimum neutralizing number is. We don't have that cutoff line," he said, adding that he suspects the immune response observed is likely to be significantly above where it needs to be to provide protection.

    That is because in clinical trials, both the Pfizer/BioNTech vaccine and a similar shot from Moderna Inc conferred some protection after a single dose with an antibody response lower than the reduced levels caused by the South African variant in the laboratory study.

    Even if the concerning variant significantly reduces effectiveness, the vaccine should still help protect against severe disease and death, he noted. Health experts have said that is the most important factor in keeping stretched healthcare systems from becoming overwhelmed.

    More work is needed to understand whether the vaccine works against the South African variant, Shi said, including clinical trials and the development of correlates of protection - the benchmarks to determine what antibody levels are protective.

    Pfizer and BioNTech said they were doing similar lab work to understand whether their vaccine is effective against another variant first found in Brazil.

    Moderna published a correspondence in NEJM on Wednesday with similar data previously disclosed elsewhere that showed a sixfold drop antibody levels versus the South African variant.

    Moderna also said the actual efficacy of its vaccine against the South African variant is yet to be determined. The company has previously said it believes the vaccine will work against the variant.
    https://www.ctvnews.ca/health/corona...tion-1.5313642..
    .
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

  5. #1945
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    Spoiler:
    Canada’s public health agency says it’s monitoring reports of two COVID-19 variants — first thought to have originated in the U.K. and California — combining to make one heavily-mutated hybrid.

    “We are aware of the reports coming out of California about the combination of two variants of the coronavirus and are closely monitoring the situation and other genetic variants of the virus that causes COVID-19,” the Public Health Agency of Canada (PHAC) said in an emailed statement to Global News.

    READ MORE: How prevalent are variants? A closer look at what — and where — they are in Canada

    “We are working with international partners, including the World Health Organization, to better understand these variants and their impact.”

    If confirmed, the mixing of the B.1.1.7 variant which was discovered in the U.K. and the B.1.429 variant first reported in California would be the first recorded COVID-19 recombination of its kind.

    Such a recombination could open the door to a vastly different wave of the pandemic, due to the U.K. variant’s high rate of transmission as well as the California variant’s mutation which allows it to be more resistant to antibodies.

    READ MORE: ‘Perfect storm’: Is Canada headed for a third wave of COVID-19?

    The recombination was first discovered in a sample of the virus in California and identified at the Los Alamos National Laboratory in New Mexico by Dr. Bette Korber, a researcher whose work has largely focused on developing an effective HIV vaccine.

    Korber, whose findings on the hybrid were presented in a meeting organized by the New York Academy of Sciences earlier this month and first reported by New Scientist, said that she saw “pretty clear” evidence of the variants’ recombination through her database of viral genomes.

    What is a recombination?
    While the idea of two or potentially more variants of the novel coronavirus combining together to create a heavily mutated version of itself may seem frightening, experts say that recombination for the most part is a natural process of viral evolution.

    Colin Furness, an epidemiologist teaching at the University of Toronto, told Global News there are two ways a virus can mutate. The first is a slow mutation through random trial and error in which single changes accumulate over a period of time.

    Furness called this “genetic drift,” or what most of the world has come to know as ‘variants.’ According to him, however, the process of recombination, is “far more radical.”

    [ Sign up for our Health IQ newsletter for the latest coronavirus updates ]

    In order for a virus to recombine, Furness said two different strains of coronavirus need to appear in the same human cell and “swab large chunks” of their genetic material, creating “large-scale changes.”
    “Someone has to be infected twice with two different strains at the same time,” he said.

    “That doesn’t sound hugely common, but then again, you put yourself on an airplane for eight hours and that’s one very plausible scenario.”

    According to Furness, recombination is most common in areas where different strains of the virus have opportunities to interact — like inside airports or in dense, popular cities.

    Amir Attaran, a professor in both the faculties of law and school of epidemiology and public health at the University of Ottawa, said that recombination is a normal thing that happens in evolution all the time.

    READ MORE: The big picture: a timeline of increasing COVID-19 variants in Alberta

    “What almost certainly happened is that a single person was infected with both a strain of the virus from England and the strain of the virus from California and inside that person’s body, somehow the two viruses came together and exchanged genes and created yet a third type of virus that bore hallmarks of both the English and the Californian variant,” said Attaran in an interview with Global News.

    Cause for concern?
    According to the experts, it’s a bit too soon to measure how much trouble such a hybrid could potentially spell for the fight against the pandemic.

    Attaran referred to an analogy of both the U.K. and California strains being the parents, and the recombination being the child. According to him, you wouldn’t be able to predict right away what effects the recombination could have — likening it to being unable to predict whether a child would be shorter or taller than its parents.

    “You have to actually see the child grow up,” said Attaran.

    Most of the time, such mutated hybrids produce mutilated versions of the virus that can no longer spread according to Furness, though there still remains the occasional possibility “for recombination to result in something that’s quite viable.”

    Whether the potential spread of this new hybrid could affect the efficacy of COVID-19 vaccines is still unknown, Furness noted that tweaking vaccines is a regular practice, especially with endemic viruses that are regularly found in particular areas.

    READ MORE: ‘It’s a forest fire’: experts predict rise of COVID-19 variant cases, warn of 3rd wave

    “We have a different flu shot every year. Well, sometimes it’s the same, but we’re prepared to reformulate the flu shot every year according to what’s circulating. That’s going to happen too with vaccines,” he said.

    “We know viruses behave this way. We know there’s been a lot of population mixing. If anything, it really ought to wake us up to the dangers of air travel.”

    Timothy Sly, a professor emeritus at Ryerson University’s School of Occupational and Public Health, noted this may be the first recombination, “but it is probably not the last.”

    “Other coronaviruses are able to do this. We have no idea what this means in terms of antibody response or vaccine success, but it is a concern.”

    Attaran said that despite the discovery of this hybrid, a bottom line still remains: “the more virus you have out there in the world and the more variance there are allowed to mix, the greater and greater chances you are taking of something brewing that becomes extremely dangerous.”

    The only way to act against the possibility of creating a much dangerous version of the novel coronavirus should be to limit the number of infections and vaccinate as much people as possible, he said.

    As of now, we are “nowhere near the theoretical lethality that a coronavirus can have,” Attaran said. “It can become much, much, much more lethal. We just have to hope it doesn’t.”

    — With files from Global News’ Kieron O’Dea

    https://globalnews.ca/news/7643533/c...tant-variants/

    .
    Ultima modifica di Blitz76; 18-02-2021 alle 04:40
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

  6. #1946
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  7. #1947
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    Nuova variante Covid si diffonde a New York, Biden estende emergenza nazionale
    Nuova variante Covid si diffonde a New York, Biden estende emergenza nazionale

    La mutazione potrebbe indebolire l'efficacia dell'immunizzazione. L'Oms: 'Gli effetti a lungo termine siano priorità. Dopo tre mesi una persona su 10 non sta ancora bene'

    Una nuova forma di coronavirus si sta diffondendo rapidamente a New York e ha una mutazione che potrebbe indebolire l'efficacia dei vaccini. Lo riporta il New York Times citando due studi, uno di Caltech e uno della Columbia.

    La nuova variante è chiamata B.1.526 e contiene una mutazione che potrebbe aiutare il virus a schivare il sistema immunitario.

    Il presidente americano Joe Biden ha intanto esteso l'emergenza nazionale a causa del Covid. "Il Covid 19 continua a causare significativi rischi alla salute pubblica e alla sicurezza del Paese. Per questo l'emergenza nazionale dichiarata il 13 marzo 2020, e iniziata l'1 marzo del 2020, deve continuare a restare in effetto dopo l'1 marzo 2021", si legge in una nota.

    Intanto la California supera la soglia dei 50.000 morti, divenendo il primo stato americano a superare il traguardo. La soglia arriva mentre una variante del virus rintracciata in California durante l'inverno si sta rapidamente diffondendo e ora rappresenta il 50% delle infezioni in 44 contee.

    Il "lungo Covid", ovvero gli effetti a lungo termine del coronavirus che colpiscono misteriosamente un numero significativo di pazienti deve essere la priorità delle autorità sanitarie. Lo ha detto il direttore dell'Oms Europa, Hans Kluge, in in una conferenza stampa. Kluge ha usato il termine inglese 'long Covid' per descrivere un fenomeno diffuso nell'area e cioè che dopo 12 settimane dal coronavirus una persona su 10 contagiata non è ancora in buone condizioni di salute.
    https://www.ansa.it/sito/notizie/pol...c1614c6ff.html

    Spoiler:
    .
    Ciascuno é l'uomo della propria idea; ci sono molte meno idee che uomini , sicché tutti gli uomini della stessa idea si somigliano , M.Proust

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