'New COVID Variant Result Of Virus' Attempt To Adapt'
Even if the virulence--or the severity--is the same as the earlier strain of the virus, we will see more patients progress to severe disease and more deaths, says K. Srinath Reddy, president, PHFI.
Mumbai: The new mutation of the SARS-CoV-2 virus, which causes COVID-19, comes with a "greater degree of infectivity", and therefore even if the virulence--or the severity--is the same as the earlier strain of the virus, we will see more patients progress to severe disease and more deaths from COVID-19, says K. Srinath Reddy, president of the Public Health Foundation India.
The variant is being found in the south and east of England, and is believed to be the reason behind the rapid surge of cases there. As a result, many countries--including India--have suspended flights to and from the UK.
Referred to as the SARS-CoV-2 VUI 202012/01 (variant under investigation, year 2020, month 12, variant 01) or B.1.1.7, the mutation has made it easier for the virus to enter cells, take over the machinery and start replicating in large numbers, Reddy said, adding that unlike the more widespread strain, the new variant "may be more infectious to young people".
Reddy was the head of cardiology at the All India Institute of Medical Sciences, and is an adjunct professor of epidemiology at Harvard. We speak with Reddy to understand if the mutation was expected, what this changes for our COVID-19 response, and if and how this affects vaccines.
Could you tell us about this new mutation, and what it means for those who contract COVID-19?
This variation is supposed to have about 17 different changes from the previous virus that has been isolated. And that seems to confer a greater degree of infectivity to this virus. Particularly, the spike protein--the key that the virus uses to enter a cell and take over its genetic machinery to reproduce itself--has been altered to some extent, making it much more infectious. Its ability to enter cells, take over the machinery and start replicating in large numbers is becoming easier. It also appears that because of multiple changes in its structure, it may be more infectious even to young people. Previously, it was thought that children and young people are less vulnerable to infection. If it is infecting children too in large numbers, then we are going to have a matter of concern. Even if they are not going to be very ill, they will carry the virus to many people.
Does it make this virus more virulent? As of now, there is no evidence [to show] that this is likely to be more virulent. It is more infectious. If the virus becomes much more infective, then it does not become more virulent because then it will exhaust its host and that is not very logical for the virus to continue its species.
So at the moment, the worry is more about the infectivity. But even if it does not become more virulent, we are concerned because if very large numbers are infected, many more than before, then even if the same fraction of people get seriously ill or die, that means, in absolute numbers, you are going to see more serious people and more likely deaths. So that is the cause for worry.
Why does this happen? Is this a logical sequence of events? When viruses like this mutate, could they only be more dangerous or could they also become less dangerous?
They can become less dangerous too. But in this particular case, the virus appears to have gathered a more infectious nature, and whether it has altered the virulence characteristics is not certain, but it does not appear to be so.
But frequent changes in the structure are well known in viruses; a couple of changes are likely every month. It is also a part of the adaptive nature of the virus. If you are trying to hem the virus in and restrict its mobility, it tends to increase its infectious nature. Maybe with all the lockdowns that we had, with stringent public health measures like masking etc., we created a bumpy road for it and it was trying to adapt to becoming more infectious. Joshua Lederberg, who got the Nobel Prize for microbial genetics in 1958, had said that it is "our wits versus their genes", [referring to microbes' ability to adapt]. So they tend to adapt quite a lot, and we need to find ways to overcome that.
In this case, it is postulated that this virus may have had ample opportunity to mutate in a person with depressed immunity. It stayed much longer in that person than it would have in another person; so it had enough time to make changes in itself.
What does higher infectiousness mean practically?
When the virus enters your body, it can be overcome quickly by your innate immunity or acquired immunity through a variety of other means. But once it starts entering the cells, particularly the cells in the respiratory tract, then it can cause damage by taking over the genetic machinery of the cell and replicating itself--and then, in that process, cause disease.
In this case, it is entering the cells much more easily. It is not giving enough opportunity for your immunity--whether it is innate immunity or acquired immunity--to overwhelm it, reject it and get rid of the infection before it causes disease. Therefore, the fact that it is gaining more easy entry into the cells means that it can cause infection translating into disease--mild or severe. Whether it is mild or severe is going to depend ultimately on your immune response. But its ability to get into the cells becomes much easier.
What could I change in my lifestyle that could make it more difficult for this virus in the new form from entering my body?
Like for any other virus--even for the other form of the virus before it mutated--you have to make sure that you are wearing a mask, not getting into crowded spaces especially in indoor areas where virus clouds can hang around. You should be able to clean your hands frequently, so that even if you pick up the virus from any surface, you are not going to be transferring it to your body.
The whole idea here is that the virus is able to move around fast from person to person, and replicate faster in the cells of the human beings because it enters more cells easily. But preventing it from reaching into our body is something that we have been practising with masking, physical distancing and hand-washing. Those are measures that we must continue to take while we build up our own innate immunity by good food, good sleep, good exposure to sunlight. These are the things that help us reject the virus even if it gets into our body.
So, if I follow all these protocols right now, as many of us have been over the last several months, there is no real need for panic. Is that correct?
There is really no need for panic. But we recognise that even with all these precautions--and not everybody is taking precautions 100%--the virus has been spreading. And the virus spreads much more when there is an opportunity by way of laxity among people. We have seen what has happened in Europe--the moment they started celebrating, it broke back again. Even in the UK, the moment they started relaxing and opening the pubs, bars and restaurants, and people started congrearting, it started spreading. Therefore, we are giving the virus an opportunity to spread.
In this particular case, this new mutant virus is able to infect more and faster--whereas if you can follow all the public health precautions, whether this virus or any other mutant, we should be able to prevent it from entering our body, and that is our major defence.
COVID-19 has been compared to many other viruses and pandemics. Is this mutation or variation different? Does it correlate to some other virus from history in its behaviour?
Different viruses mutate at different rates. Even common cold viruses change, and that is why every year or two, you change your influenza vaccine. Viruses do change--sometimes they become more virulent, sometimes less virulent; sometimes they become more infectious, sometimes less infectious.
How long will this virus take to change its behaviour? We do not know. But it is frequently adapting and changing its mutation. After all, it is trying its best to stay in our global population. The way it can do that--when we are trying to create roadblocks for it--is to change the way it can infect more people. So that is what it is trying to do. But we have to try and keep it away from us, till we get vaccines or till it changes into a form that learns to coexist with us without causing much damage.
Vaccines are already being administered in England, the US and Canada, and other countries are also getting them. India will also soon start getting them. Can the vaccines effectively counter this mutation or future mutations?
The mRNA vaccine or the virus-carrier types of vaccine (such as that being developed by AstraZeneca) are all targeting the spike protein of the virus. The spike protein is the key that the virus uses to get into the cell. If your vaccine is able to deactivate or destroy the spike protein because of the immunity that is created both by the way of antibodies as well as T-cell immunity, then the vaccine should continue to be effective even if the spike protein has slightly changed its character. It is the spike protein that gives the virus the crown. So if the virus still does not shed its crown, it is likely [to be effective].
The inactivated virus vaccine, which targets the virus itself and not the spike protein, may not be affected much by this kind of mutation. And we are also producing that in India. In fact, the ICMR vaccine is an inactivated virus vaccine. So theoretically, it should be able to deal better even with these kinds of mutations.
Only when you are targeting a particular portion of the virus, like the spike protein, and if the spike protein is markedly altered in structure, is there a danger that the vaccine may not be effective. Right now, we do not see that danger existing with the nature of mutations in this variant.
India has suspended flights to and from the UK, and passengers arriving from the Middle East and European countries are being asked to quarantine. In cities like Mumbai, there is curfew now going into New Year's Day because the risk of congregation is higher. What do you think we should be doing from a public health point of view, particularly within India, given that we have the new mutation hanging over us?
While this variant was introduced to us in December 2020 by the government of the UK, they have now said that it has been detected since September in the UK. And if it was around in September, we do not know how much it has spread since then. We had people coming in from the UK and elsewhere. So it is possible that the virus could have spread to other countries. It is only the countries that are regularly looking at the viral structures very seriously in their testing laboratories that are able to detect these changes. Even the CDC [Centers for Disease Control and Prevention] in the US has said that their testing labs are not routinely looking for these mutations and therefore, they are not sure whether the virus has entered the US and is spreading there. So we are unsure that just by stopping the flights right now, we have prevented the virus from entering.
However, it has been said that so far, there is no evidence that such a mutant has been detected in India. And if that is so, it is good for us. But we need to maintain the precautions certainly. As flights resume what we really need to do, of course, is to characterise the nature of the virus that is coming in detected in any test in the big laboratories, but particularly emphasise the screening of incoming passengers for any symptomatic COVID or test them. And also maintain our regular defence--masks, physical distancing and hand-washing. Those are the things that need to happen, whether this mutant or any other mutant.
When you look at data over the last two to three months, overall case numbers are falling. We are now at 20,000-30,000 cases per day, which is much lower than what it used to be. Deaths are much lower. Would this have continued? Were we on a good path, at least till this point?As I mentioned in the past, I look at deaths with greater confidence than just case numbers. Cases vary with testing criteria and methods. If you look at the overall count, definitely, it appeared that the epidemic is on the wane. It was coming under control in any case. Now, whether this [new mutation] is going to cause a setback, we have to wait and see. But if we maintain our public health vigil more than anything else, then I think we should continue our path of progress.
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