‘Superspread’ events help mutations achieve a breakthrough «kleinezeitung.at

German and American researchers analyzed the genesis and spread of virus variants based on 62,000 sequences of Covid-19 pathogens.

11:39 AM, August 20, 2021

While the flu spreads evenly each winter, Covid-19 is different. This also applies to that The sudden emergence and spread of SARS-CoV-2 variants. Now a team of German-American scientists has proven it above all ‘spread’ events play a crucial role. So mask-wearing, hygiene and other measures remain important.

the A scientist from the German Cancer Research Center (DKFZ / Heidelberg) And from Institute of Applied Biomedical Sciences (San Diego/California) Investigate the emergence of SARS-CoV-2 variants in the US population using data from the US National SARS-CoV-2 Sequence Database. the Mixture of mutations plus ‘widespread of events’ It therefore fuels the spread of genetic viral variants in the population.

62,000 pathogen sequences for Covid-19

The researchers analyzed the genome data from above 62,000 SARS-CoV-2 isolates from 42 US states between January 2020 and April 2021. As early as March 2020, the team documented the first genetic aberrations from the original “Wuhan variant,” which was no longer detectable as of early summer 2020. The number of mutations per virus genome gradually increased over time. The researchers used some key mutations to define 14 different species, some of which were differently distributed in the United States.

In the summer of 2020, researchers observed a surprisingly strong accumulation of mutations. “We suspect the sequence of something called “Super Dealer Events” cause these accumulations. As a result, rare mutations, initially occurring only in less than one percent of all infected people, can suddenly spread widely.”

Not classified as problematic

In the last quarter of 2020, a large number of new mutations appeared in the spiky protein gene. These 20 or so mutations were not classified as problematic and in some cases were so rare that it was in fact expected that they would be lost again. Instead, the frequency of most of these mutations increased to significant levels. “All of these mutations spread through the population,” Papavasiliou warned. “We have to realize that an additional ‘super-spreading’ event could be enough for them to spread far and wide and create new taxa.”

At the end of 2020, the first came with B.1.1.7, initially referred to as the British variant ‘The worrying alternative’ in the US population. The genetic diversity of viruses has increased by leaps and bounds. The researchers were shocked to discover that such alarming types of viruses accumulate mutations again in just three months. Initially, widespread use of the “British variant” kept other SARS-CoV-2 mutations in check. Then the now dominant delta variant of Covid-19 pathogens evolved.

The SARS-CoV-2 genome was considered fairly stable at the start of the epidemic. But this should only apply to a limited extent. Based on careful analysis of mutation patterns, the scientists were able to identify a mechanism that could be a driver of genetic diversity: enzymes of the APOBEC group (proteinase B enzymes, which modify mRNA; note) belong to the innate defense of mammals and humans against infections. They attack the viral genome and thus can render the pathogen harmless. But this, in turn, is a selection pressure that fuels the emergence of new mutations.

protect inside the house

“The evolution of SARS-CoV-2 will continue. Mutations happen all the time, and “superspreader” events help them break through. In order to prevent the world from being constantly plagued by increasingly unpleasant virus variants, we must continue to protect ourselves from infection, Especially indoors and in areas with poor vaccination protection.Summarize the World (Plus One 2021, DOI: https://doi.org/10.1371/journal.pone.0255169). It was assumed for some time that 20 percent of infected people are responsible for 80 percent of infections.

According to scientists, without SARS-CoV-2 vaccines with full immunization (all necessary vaccine doses) in the United States due to the delta variant, there would have been a risk of catastrophe in the recent past. You should strengthen vaccination protection. In addition, vaccines with a broader effect should be developed. Wearing masks indoors, avoiding mass events and social distancing will be of great importance especially this coming fall.