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What do we know and what should we know about this evolving virus
Variants of concern, variants of interest
Elaborating on the various classifications of SARS-CoV-2, Professor and Consultant in Clinical Immunology and Allergy at the Institute of Immunity and Transplantation and Health Services Laboratories, UK, and Nawaloka Hospital Research and Education Foundation, Sri Lanka, Prof. Suranjith Seneviratne, said that there are two types of variants, namely ‘variants of concern’ and ‘variants of interest.’
He told The Morning that there could be about 4,000 different variants of the SARS-Cov-2 virus, and that most of them have no effects, and therefore, they have not been even classified.
Explaining the difference between the two categories, Prof Seneviratne added, “Initially, when a variant is discovered, scientists conduct various studies including lab studies on the effects of the virus on the people who have been vaccinated. Until they conclude studies, they call the virus a variant of interest. If you look at the Indian variant, it was initially a variant of interest. Once the scientists are more definite about the variant and its effects and severity, it is called a variant of concern. Some variants have no effects, and they are, therefore, neither variants of interest nor variants of concern.”
According to the national public health agency of the United States, Centres for Disease Control and Prevention, several factors are taken into account when classifying a variant as a variant of concern, and they are, widespread interference with diagnostic test targets, evidence of substantially decreased susceptibility to one or more class of therapies, evidence of significant decreased neutralisation by antibodies generated during previous infection or vaccination, evidence of reduced vaccine-induced protection from severe disease, evidence of increased transmissibility and evidence of increased disease severity.
Variants of concern of SARS-CoV-2, according to Prof Seneviratne, are the UK variant, South African variant, Brazil variant, and the Indian variant, which is divided into three different types.
According to foreign media, the world Health Organisation (WHO) has last week classified the Indian variant as a ‘variant of global concern.’ It is reported to have spread to over 30 countries, and it spreads faster than other variants of the virus. WHO classified the Indian variant as a variant of concern in a context where India keeps reporting around 400,000 new Covid-19 cases and 4,000 deaths every day.
“When it comes to naming variants, instead of the scientific names, various other names such as the Indian variant or the UK variant are used, in order for the ordinary people to understand,” he said, adding that these are the areas where the variant in question was first detected, not where the variant is most prevalent.
How a variant is created?
Prof. Seneviratne explained how a variant is created: “When cells, for example virus or bacteria, divide and multiply, the genetic material has to be replicated, and errors occur during what we call the replication. When it comes to human cells, these errors are corrected very rapidly because of the mechanism called proofreading. However, when it comes to bacteria and viruses, the proofreading is less. When it comes to Ribonucleic Acid (RNA) viruses, the chance of there being an error is higher than in what we call a Deoxyribonucleic Acid (DNA) virus. The SARS-CoV-2 virus is an RNA virus, and when RNA viruses multiply (duplicate), errors can occur. However, the SARS-CoV-2 RNA virus has less errors compared to other viruses such as the Human Immunodeficiency Virus (HIV).”
The changes caused by these errors vary, and can range from no to severe changes, he said, explaining that these changes are the cause of variants.
He added: “Some of the errors have no effects and they do not cause any changes to the virus, while some of the changes make the virus less effective or weak. Some of the changes make the virus produce variants (changes from the original virus) and those variants can spread faster from person to person, bind to the cell very well so that they can spread, cause severe diseases, cause the diagnostic tests to be unsuccessful and can affect treatments or can even affect the vaccines rendering the vaccines not very effective.”
Double mutant variants
When it comes to new variants of SARS-CoV-2, the world started talking about mutations and doubt mutants, and some claimed that doula mutant variants are more aggressive and may be difficult to deal with.
When asked what a double mutant variant is, Prof. Seneviratne explained: “Double mutant variants became well-known in relation to the Indian variant. If we take into consideration the structure of a virus, spike protein is the part that binds to a cell, and a virus has to go into a cell to be able to multiply as it cannot do so in open air. Once the protein is bound to the cell, the virus goes in. There is a part of the protein called Receptor Binding Domain (RBD). When it comes to double mutants there are changes in different genes that lead to the protein. The change first occurs in the genes of the virus. The virus has RNA and the changes occur in the RNA. Because of that, protein can also change. What happened was there were two critical mutations in what we call the RBD of the spike protein, and because of those two mutations, it is called ‘double mutation’. I think there were altogether about 16 mutations in the whole RNA.
“Double mutant variant does not mean that the virus has only two mutations and other viruses have fewer mutations. It means that there are two critical ones. Initially, in March, a critical situation started in India and the country started finding more and more of double mutant variant cases. They said it was a variant of interest, and when they investigated it, they found that it had been spread to a lot of countries including the UK. UK scientists studied it and very recently found that the Indian variant is the one that is increasing a lot in the UK at the moment, especially type B of it. The UK says that it could be equally or more transmissible than the UK variant.
“The original variant is the Wuhan variant. In November last year, suddenly a large number of cases were reported in England, and they detected the UK variant. The high number of cases is caused by the virus’ ability to easily transmit from one person to another. The UK variant is quite transmissible but other than that, it causes other issues as well; but, it does not affect the vaccine. Now they have found that the Indian variant, especially type B, is equally or more transmissible as the UK variant. The exact parentage of transmissibility is still being investigated and is not known as of yet. However, the Indian variant is believed to be more transmissible, and that is very important because that means that it may quickly become the most prominent variant in the UK. Those two mutations can potentially affect the immunity of a person. However, it has not been confirmed yet. Studies are underway to find out whether people who have had Covid-19 in the past can get it again because their immunity drops or whether it can affect how the vaccine works. However, we know for certain that the South African variant has the ability to affect the vaccinated.”
He noted that Sri Lanka too has to be extremely careful of the Indian variant, since it has entered Sri Lanka. Early this month, local researchers confirmed that Sri Lanka has detected its first Covid-19 case of the Indian variant in a person who had returned from India. He had tested positive when he was in a quarantine centre.
New variants vs. safety guidelines
Can the initially introduced Covid-19 safety guidelines effectively protect against the new variants is a question raised by many after the increase in Covid-19 cases and the detection of new variants in Sri Lanka. Authorities recently recommended new safety guidelines – they recommended maintaining two-metre distance between two persons as opposed to one-metre distance, and wearing two face masks as opposed to one.
When asked whether the said measures are enough now that Sri Lanka has commenced the vaccination drive, or do the transmissibility and severity of the new variants call for newer or stricter safety precautions, Prof. Seneviratne said that the adhering to existing safety precautions and continuing the vaccination drive are both equally important and should go hand in hand.
He explained: “Every country has identified two ways to deal with the pandemic. First of all there are Covid-19 safety guidelines such as maintaining social distancing, wearing face masks, sanitising hands and isolating people at risk, and that should go hand in hand with the vaccination programme. If you only adhere to safety guidelines, cases will drop. But as soon as you relax these regulations, cases will increase. Also, if you only do the vaccination programme, people would be all over the place, and it will not be helpful. Both measures should go hand in hand, and all countries recognise that. However, in different countries, the stringency of these measures varies. While some countries implemented very strict measures, some countries imposed very relaxed measures. Also, merely having guidelines or imposing regulations is not enough, and they have to be implemented properly. In order to do that, people have to be educated about the benefits of following those guidelines and consequences of not following them. That has to be communicated very clearly to the people. There is a massive shortage of vaccines in the world, not only in Sri Lanka, and that makes the safety guidelines more important. The benefits of the vaccine should also be clearly conveyed to the people.”
He also noted the people should be made aware of the difficulties faced by healthcare providers when a large number of cases arise suddenly, especially in a context where a massive amount of resources have to be allocated for people infected with Covid-19. He noted that lack of resources affected Italy and now India, and that the people could see the repercussions of increasing Covid-19 cases. “Sri Lanka should also be very vigilant about the limited resources,” he stressed.
Symptoms/complications of different variants
In response to a question whether the symptoms or complications of different variants of the virus may vary, Prof. Seneviratne said: “It appears to be. When it comes to differences, transmissibility is number one; secondly, symptoms and severity of the disease may also vary. Certain variants, such as the UK variant, may cause a bit more severe symptoms, while the South African variant does not change the severity of the disease. People are dreading variants that may cause immediate, severe symptoms; but thus far, researchers have not found that sort of variant. But definitely one or two variants increase the severity of the disease.
According to researchers, even though the most common symptoms of Covid-19 are fever, sore throat and dry cough, there are a number of less common symptoms including diarrhoea, headaches, body aches, loss of taste or smell or rashes.
The emergence of newer and more contagious variants of the virus in Sri Lanka is indeed unfortunate. However, whether we like it or not, the country has to fight the Covid-19 pandemic, and deal with the risk of more variants entering the country.
As those who spoke with The Morning pointed out, the vaccine alone cannot protect against Covid-19, and whether a person has obtained the vaccination or not, they can still contract and spread Covid-19. The ultimate goal is to defeat Covid-19, and if the people adhere to safety guidelines, the nature of variants entering the country would be of no concern.