MUTATION ISSUE OF CORONA

 

MUTATION ISSUE OF CORONA

mutation issue

Survival of the fittest the great line said by the great naturalist, geologist and biologist Charles Robert Darwin. Is taken very seriously by corona virus that’s why it mutated itself and had appeared in a new form with new surprises. Viruses mutate all the time, including the novel coronavirus that’s caused the global pandemic.

But a variant that emerged in southeast England in September is causing particular concern, leading to an emergency lockdown in London over Christmas and prompting countries including Canada, France and Germany to halt flights and suspend rail links to the U.K.

The variant is unusually highly mutated.

The most likely explanation is the variant has emerged in a patient with a weakened immune system that was unable to beat the virus. 

Instead their body became a breeding ground for the virus to mutate. 

  MUTATION ISSUE OF CORONA

UNDERSTANDING THE MUTATION 

Health officials in the United Kingdom and around the world are worried about a new, seemingly more contagious variety of SARS-CoV-2 (the virus that causes Covid-19), which has emerged in the country and was announced over the weekend. The evidence that this new strain spreads more easily between people is not rock solid, but it’s concerning enough to have forced dramatic action.

An increasingly common mutation of the novel coronavirus found in Europe, North America and parts of Asia may be more infectious but appears less deadly, according to a prominent infectious diseases doctor.

Paul Tambyah, senior consultant at the National University of Singapore and president-elect of the International Society of Infectious Diseases, said evidence suggests the proliferation of the D614G mutation in some parts of the world has coincided with a drop in death rates, suggesting it is less lethal.

mutants

"Maybe that's a good thing to have a virus that is more infectious but less deadly," Tambyah told Reuters. Tambyah said most viruses tend to become less virulent as they mutate. "It is in the virus' interest to infect more people but not to kill them because a virus depends on the host for food and for shelter," he said. Scientists discovered the mutation as early as February and it has circulated in Europe and the Americas, the World Health Organization said. The WHO has also said there is no evidence the mutation has led to more severe disease.

The new mutation of the coronavirus, that has emerged in the United Kingdom, has not been seen in India so far, officials from the Union Health Ministry told the media on Tuesday. The government also allayed fears over the new mutant strain stating that it does not affect the severity of the disease, but affects the transmissibility and infectiousness of the virus. Assuring that there is no need to panic, officials from the Health Ministry maintained that it is important to follow COVID-19 norms and precautions.

 MUTATION ISSUE OF CORONA 

What is N501Y?

In simple words, the amino acid represented by the letter N, and present at position 501 in the coronavirus genetic structure, has been replaced in that position with another amino acid, represented by Y. The position where this alteration has taken place is in the spike protein’s receptor-binding domain. (It is the spike protein of the virus that binds with the human receptor.)

Therefore, the mutation has increased the binding affinity of the coronavirus. The mutated virus reportedly accounts for 60% of recent infections in London.

According to the Global Initiative on Sharing Avian Influenza Data (GISAID) database, the same mutation in the receptor binding domain has been independently reported in several countries including South Africa and Australia. Sequence analysis has shown that this mutation originated separately in the UK and South Africa.

  MUTATION ISSUE OF CORONA

And what are P681H and HV 69/70?

P681H: This mutation has occurred in the amino acid present at 681 — another position in the receptor-binding domain. Here the amino acid P has been replaced with H. The US Centres for Disease Control (CDC) has said this is a site “with high variability in coronaviruses”, and this specific mutation has also emerged spontaneously multiple times. The WHO has said this mutation is of “biological significance”.

Researchers have earlier shown that this mutation can promote entry into respiratory epithelial cells and transmission in animal models.

Recent samples sequenced at the African Centre of Excellence for Genomics of Infectious Diseases, Redeemer’s University, Nigeria has shown the P681H sequence there. However, researchers say that at present, they “do not have evidence to indicate that the P681H variant is contributing to increased transmission of the virus in Nigeria”.

HV 69/70: This mutation is the result of a deletion of amino acids at positions 69 and 70. These positions are again in the spike protein of the virus. This deletion has been observed in France and South Africa as well. The CDC has said: “This double deletion has occurred spontaneously many times, and likely leads to a change in the shape of (i.e., a conformational change in) the spike protein”.

Researchers on behalf of COVID-19 Genomics Consortium UK (CoG-UK), which red-flagged the new variant in the UK, have said in their preliminary report that this deletion was also seen in a mink-associated outbreak in Denmark. In humans, this deletion has been associated with another mutation, N439K, which again occurred the receptor-binding domain.

The WHO has highlighted that this deletion can affect the performance of some RT-PCR tests that detect the novel coronavirus.

 MUTATION ISSUE OF CORONA

Why is this variant causing concern?

Three things are coming together that mean it is attracting attention:

• It is rapidly replacing other versions of the virus
• It has mutations that affect part of the virus likely to be important
• Some of those mutations have already been shown in the lab to increase the ability of the virus to infect cells

All of these come together to build a case for a virus that can spread more easily.

However, we do not have absolute certainty. New strains can become more common simply by being in the right place at the right time - such as London, which had only tier two restrictions until recently.

But already the justification for tier four restrictions is in part to reduce the spread of the variant.

"Laboratory experiments are required, but do you want to wait weeks or months [to see the results and take action to limit the spread]? Probably not in these circumstances," Prof Nick Loman, from the Covid-19 Genomics UK Consortium, told me.

 

  MUTATION ISSUE OF CORONA

Will the vaccines work against the new variant?

Almost certainly yes, or at least for now.

All three leading vaccines develop an immune response against the existing spike, which is why the question comes up.

Vaccines train the immune system to attack several different parts of the virus, so even though part of the spike has mutated, the vaccines should still work.

the only hope

"But if we let it add more mutations, then you start worrying," said Prof Gupta.  

"This virus is potentially on a pathway for vaccine escape, it has taken the first couple of steps towards that."

Vaccine escape happens when the virus changes so it dodges the full effect of the vaccine and continues to infect people.

This may be the most concerning element of what is happening with the virus.

This variant is just the latest to show the virus is continuing to adapt as it infects more and more of us.

A presentation by Prof David Robertson, from the University of Glasgow on Friday, concluded: "The virus will probably be able to generate vaccine escape mutants."

That would put us in a position similar to flu, where the vaccines need to be regularly updated. Fortunately the vaccines we have are very easy to tweak.

  MUTATION ISSUE OF CORONA

FAQ

Q. How common is this variant?

=> Believed to have been first detected in September, the strain moves fast and is becoming the dominant variant, causing over 50% of infections in London by December, said Patrick Vallance, UK government’s chief scientific adviser.

Q. Is mutation in a virus abnormal?

=> viruses mutate all the time. Most of the new variant die out. Sometimes they spread without altering the virus behaviour. Occasionally, they trigger dramatic changes.

Q. Is the new variant more dangerous?

 => The new variant is spreading more rapidly than the original version, but it is not believed to be more deadly. There is currently no evidence that this strain causes more severe illness, as per an official.

Q. Is it found only in UK?

 => While the variant is found across the UK, it is heavily concentrated in London and south east England. Instances

Of the same variant have been reported in Denmark, Australia and Netherlands.

Q. How many days or years virus live in a lab?

 => researchers say that the virus may remain for 28-30 days in the lab which is equivalent to on around one month. The findings from Australia's national science agency suggest SARS-Cov-2 can survive for far longer than thought.