SARS-COV-2 Mutated Variant 20A.EU1 With A222V Mutation On It Becoming Prevalent Circulating Strain In Europe And Could Be More Dangerous!
: Scientists from the University of Basel-Switzerland, Biomedicine Institute of Valencia (IBV-CSIC)-Spain and SeqCOVID-SPAIN consortium have identified a novel SARS-CoV-2 variant that has spread widely across Europe in recent months. The research findings were published on a preprint server and have yet to be peer-reviewed. https://www.medrxiv.org/content/10.1101/2020.10.25.20219063v1
Although the researchers in the study say that there is no evidence to date that indicate this variant could be more dangerous and its spread may give insights into the efficacy of travel policies adopted by European countries during the summer, Thailand Medical News found that of the two key mutations of this 20A.EU1 variant, ie the A222V mutation on the spike protein and the A220 A220V in the nucleoprotein, the A222 mutation could be dangerous as its amino acid residue 222 is located within the B cell immunodominant epitopes which was already previously identified in another study. The A222V mutation may affect the structure of these epitopes
This could mean that this strain could have an immune evasive advantage in terms of B cell and T cell responses. Further detailed studies are urgently warranted on this. There could also be implications in terms of vaccine and therapeutic developments. As for the mutations on the ORF14 protein and also on the nucleoprotein we at TMN hypothesize that they could have a role in term of terms of interferon inhibition in the human host and again this needs further studies for verification.
At present in Europe alone, hundreds of different variants of the new coronavirus SARS-CoV-2 are currently circulating, distinguished by mutations in their genomes. However, only very few of these variants have spread as successfully and become as prevalent as the newly identified variant, named 20A.EU1.
The study team analyzed and compared virus genome sequences collected from COVID-19 patients all across Europe to trace the evolution and spread of the pathogen. Their analysis suggests that the variant originated in Spain during the summer. The earliest evidence of the new variant is linked to a super-spreading event among agricultural workers in the north-east of Spain.
This new variant moved into the local population, expanding quickly across the country, and now accounts for almost 80% of the sequences from Spain.
Dr Emma Hodcroft of the University of Basel,lead author of the study told Thailand Medical News, "It is important to note that there is currently no evidence the new variant's spread is due to a mutation that increases transmission or impacts clinical outcome.”
The study team believes that the variant's expansion was facilitated by loosening travel restrictions and social distancing measures in summer.
Professor Dr Iñaki Comas, co-author on the paper and head of the SeqCOVID-Spain consortium added, "We see a similar pattern with this variant in Spain as we did in the spring. One variant, ai
ded by an initial super-spreading event, can quickly become prevalent across the country."
It was found that from July, 20A.EU1 moved with travelers as borders opened across Europe, and has now been identified in twelve European countries. It has also been transmitted from Europe to Hong Kong and New Zealand. While initial introductions of the variant were likely from Spain directly, the variant may then have continued to spread onward from secondary countries.
Presently, 20A.EU1 accounts for 90% of sequences from the UK, 60% of sequences from Ireland, and between 30 and 40% of sequences in Switzerland and the Netherlands. This makes this variant currently one of the most prevalent in Europe. It has also been identified in France, Belgium, Germany, Italy, Latvia, Norway, and Sweden.
Detailed genetic analysis indicates that the variant travelled at least dozens and possibly hundreds of times between European countries.
Professor Tanja Stadler of ETH Zürich, one of the study's principal investigators said,"We can see the virus has been introduced multiple times in several countries and many of these introductions have gone on to spread through the population. This isn't a case of one introduction just happening to do well."
Although though the rise in prevalence of 20A.EU1 corresponds with the increasing number of cases observed in many European countries this autumn, the study's authors caution against interpreting the new variant as a cause for the rise in cases.
Professor Dr Richard Neher of the University of Basel, one of the study's principal investigators commented, "It is not the only variant circulating in recent weeks and months. Indeed, in some countries with significant increases in COVID-19 cases, like Belgium and France, other variants are prevalent."
Detailed analysis of the summertime SARS-CoV-2 prevalence in Spain and travel data show that these factors may explain how 20A.EU1 spread so successfully. Spain's relatively high number of cases and popularity as a holiday destination may have allowed multiple opportunities for introductions, some of which may have grown into larger outbreaks through risky behaviors after returning home.
The researchers highlight the importance of evaluating how border controls and travel restrictions worked in containing SARS-CoV-2 transmissions over the summer, and the role travel has played.
Dr Hodcroft added, "Long-term border closures and severe travel restrictions aren't feasible or desirable but from the spread of 20A.EU1 it seems clear that the measures in place were often not sufficient to stop onward transmission of introduced variants this summer. When countries have worked hard to get SARS-CoV-2 cases down to low numbers, identifying better ways to 'open up' without risking a rise in cases is critical."
This new variant was first identified by Dr Hodcroft during an analysis of Swiss sequences using the 'Nextstrain' platform, developed jointly by the University of Basel and the Fred Hutchinson Cancer Research center in Seattle, Washington.
The 20A.EU1 variant is characterized by mutations that modify amino-acids in the spike, nucleocapsid, and ORF14 proteins of the virus.
Although the present state of knowledge does not indicate 20A.EU1's spread was due to a change in transmissibility, the study team are currently working with virology labs to examine any potential impact the spike mutation, known as S:A222V, may have on the SARS-CoV-2 virus' phenotype. They also hope to soon receive access to data that would allow them to assess any clinical implications of the variant.
Significantly, the researchers emphasize the importance of monitoring the rise of new variants like 20A.EU1 closely.
Dr Neher added, "It is only through sequencing the viral genome that we can identify new SARS-CoV-2 variants when they arise and monitor their spread within and between countries. But the number of sequences we have varies widely between countries, and we might be able to identify rising variants sooner with faster and more regular sequencing efforts across Europe."
Thailand Medical News would like to add that here has been lack of monitoring of SARS-CoV-2 mutations and emerging variants and also a lack of research in understanding these mutations and their implications in the pathogenesis and interactions with the human host immune system and cellular pathways. More resources have to be channeled into such research if we ever want to stamp out this COVID-19 pandemic.
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