The variant carries 14 defining mutations, seven of which are in the spike protein - the protein that mediates the entry of the virus into human cells. This is a relatively large number of changes compared to the many versions of the virus around the world
Lucy van Dorp, Senior Research Fellow, Microbial Genomics, UCL
A new variant of SARS-CoV-2, the virus that causes the disease COVID-19, has begun to spread rapidly in parts of the UK.
The British government has put the south-east of England, including the capital London, under new and stricter restrictions on the corona virus - known as Tier 4. People in the areas defined as Tier 4 will not be able to meet with anyone outside their home on Christmas, while in the rest of the country within the framework of the reduced restrictions it is allowed The meeting, but that too, only on Christmas Day itself.
Prime Minister Boris Johnson and his chief scientific advisers said the new mutation could increase the infection rate of COVID-19 by up to 70% and increase the R number by 0.4%.
What does the new discovery mean? The Conversation asked Lucy van Dorp, a microbial genomics researcher and pathogen evolution expert at University College London, some key questions about what we know at this point in time.
What do we know about this new version?
“The new UK version, known as VUI-202012/01 or B.1.1.7, was first detected in Kent County on September 20. Matt Hancock, the health minister, first announced the version's existence on December 14. The version carries 14 mutations, seven of which are in the spike protein - the protein that mediates the entry of the virus into human cells. This is a relatively large number of changes compared to the many versions of the virus around the world.”
"So far, genetic profiles - or genomes - of this variant have been discovered mainly in the UK, but there have also been several confirmed cases of this sequence in Denmark and two cases in Australia. There were also reports of a case in the Netherlands. In all of these countries massive sequencing of the virus genome is underway, it is very possible that these observations do not reflect the true distribution of this variant of the virus, which can exist undetected elsewhere. We will know more as more genomes are sequenced and shared.”
"Thanks to the efforts of data sharing, genomic tracking and testing results of COVID-19 in the UK, it appears that this variant is now becoming dominant over existing variants of the virus and may be responsible for an increasing rate of corona infections in parts of the country, particularly in areas where A rapid increase in the number of cases."
"It is always difficult to separate cause and effect in these cases. Because there could be other reasons for the increased infection in those areas. Although this is still a possibility, there are clearly enough observations to date of this variant to warrant very careful characterization, surveillance, and interventions to curb infection.”
A combination of mutations may provide the virus with an advantage
Is the virus from the new version more dangerous?
"Chris Whitty, the UK's Chief Medical Officer, has clearly stated that there has been no evidence so far that it changes the severity of the disease, either in terms of mortality or the severity of the disease in those infected. The study examining this is in progress."
How do mutations occur in viruses?
"Mutations are a natural part of the development of viruses. In the case of SARS-CoV-2, these mutations can arise due to random errors during virus replication, change due to contact with antiviral proteins in people's bodies, or undergo recombination. Although so far no signs of recombination in SARS-CoV-2 have been found.”
"Most viral mutations may not cause any effect. For example, when our team studied individual mutations in more than 50,000 genomes from the first wave of the epidemic, we did not identify any that significantly changed the viral fitness - the ability of the virus to survive and reproduce."
However, occasionally a mutation, or in this case a particular combination of mutations, may succeed and provide the virus with a new advantage. Viruses carrying these combinations of mutations may then increase the frequency of their spread by natural selection given the right epidemiological environment.
The mutations could have occurred in the body of one chronic patient
Where did the version come from?
Right now, we don't know. So far, scientists have not identified any closely related viruses to support the theory that the variant came from abroad. The observed mutation patterns are more supportive of a likely prolonged period of adaptive evolution in Britain based on the current data.
Similar patterns of mutation to those observed in the evolution of SARS-CoV-2 in corona patients who have chronic diseases and their immune systems are weak. The current hypothesis is that such a scenario of chronic infection in one patient may have played a role in the formation of this variant. This will continue to be investigated.
How many variations of SARS-CoV-2 have been discovered?
There are many thousands of SARS-CoV-2 viruses that differ on average by only a small number of defining mutations. This remains true because the globally circulating SARS-CoV-2 has little genomic diversity. Subtleties in the defining mutations can under different circumstances cause changes in infection patterns.
Why is the situation different this time?
"It is important to note that many of the mutations that define the British version were observed in SARS-CoV-2 earlier. However, the change this time is that the genome contains a combination of an unusual number of defining mutations. One of these mutations, N501Y, was previously found to increase the binding of the virus to receptors in our cells. N501Y was found in the first sequence of the virus in Brazil in April 2020 and is now also spreading in South Africa after having evolved there independently in a separate lineage."
"The gene deletions identified in the spike protein of B.1.1.7 appeared in many lineages of the virus with high frequency, and they are also observed in chronic patients where they may change the body's immune memory. These deletions are also associated with other mutations in the binding region of the spike protein, including those observed in winter farms in Denmark. This mutation has also demonstrated the ability to penetrate the human immune system. B.1.1.7 also includes a truncated ORF8 gene, when deletions in this region caused a decrease in the severity of the disease."
We may need to get vaccinated every year
What does the mutation mean regarding the effectiveness of the vaccines that began to be distributed in recent days?
"Right now we don't know. Although we need to be sure that the vaccines elicit a broad antibody response to the entire spike protein, it is therefore expected that their efficacy will not be significantly compromised by mutations. This was also tested during the development of the vaccine."
"However, there is a growing body of evidence that other species of seasonal coronaviruses (those that usually cause the common cold) exhibit some ability to escape the immune system for longer periods of time. It is therefore conceivable that we may reach a point where we will be required to update our COVID-19 vaccines, as we do for the flu, to reflect the versions that are in circulation at the time. It is too early to say whether this will be the case now, but extensive genome sequencing and data sharing may help answer this question.”
More of the topic in Hayadan:
- The corona virus accumulates mutations - and one of them is very disturbing
- Genomic research from the University of Tel Aviv: about 70% of the infection chains of the corona originate from the USA and the rest from Europe
- A cocktail of nano-antibodies produced from the animal will succeed in stopping the corona virus efficiently and at low cost
One response
We need an urgent mutation. The first version of the virus is too slow to justify a dictatorship.