• An overview of an ongoing debate based on int’l. research, expert opinions, and facts and related recommendations   

BY Sumudu Chamara The evolving nature of Severe Acute Respiratory Syndrome Coronavirus Two (SARS-CoV-2), the virus that causes Covid-19, has been highly noticeable since the beginning of the Covid-19 pandemic, and experts say that this is one of the reasons that have made it difficult to manage the pandemic.  While the world is more than familiar with new and more aggressive Covid-19 variants, scientists fear that parts of the Omicron (B.1.1.529) and Delta (B.1.617.2) may combine, and form more aggressive variants. Early this month, the global medical community expressed fears of the emergence of such variants they call “super variants”, which are believed to be more dangerous than the recently emerged Omicron variant, which is currently known as the most dangerous variant.  There is a discussion around it in Sri Lanka as well, on the basis that the Omicron variant has already entered Sri Lanka, and the Delta variant currently being the dominant variant in Sri Lanka.   Sri Lanka’s health experts have also commented on the matter, in a context where there is a discussion about the same among the public, especially on social media platforms. In response to reports that there is a potential for a person to develop a superior Covid-19 variant if infected with the Omicron and Delta variants, Health Ministry Communications Director, Public Health Services Deputy Director General, and Disaster Preparedness and Response Division Head Dr. Hemantha Herath said: “There are certain theoretical possibilities. Though there are reports of a superior variant, it is very difficult for us to say whether it really happens or not.”  Adding that it is difficult for the Ministry to express a definite opinion in this regard, he said that it has not been scientifically proven that such conditions occur. He called this a “theoretical probability”. Warnings of Omicron-Delta ‘super variant’ Moderna Chief Medical Officer Dr. Paul Burton had recently revealed that the creation of this super variant is possible, in the event the Omicron and Delta variants infect a person at the same time.  Speaking before the UK Parliament’s Science and Technology Committee recently, Dr. Burton had stated that the high numbers of Delta and Omicron variant cases currently circulating in Britain had made this more likely, and that it was certainly possible that the two variants could swap genes and trigger an even more dangerous Covid-19 variant. The British media outlet Daily Mail quoted Dr. Burton, as having said: “There is certainly data; there have been some papers published again from South Africa earlier on from the pandemic when people – and certainly immunocompromised people – can harbour both viruses (Delta and Omicron variants). That would be possible here, particularly given the number of infections that we were seeing.” The media report further said that researchers have warned that these events, scientifically called “recombination events”, are possible, even though they require very specific conditions and the coincidence of mostly uncontrollable events. It added that only three Covid-19 strains created by viruses swapping genes have ever been recorded, with the virus instead mostly relying on random mutations to make more variants. Meanwhile, speaking about the same, New South Wales University, Australia virologist Peter White had recently warned of the inevitability of a new Covid-19 super variant. During an online discussion about the damages the Omicron variant can do, he said: “The thing I think that people have not realised is that we are going to see large-scale mutations, known as recombination in virology terms, between variants of concern. So, if we mix the best bits of Delta with the best bits of Omicron, we might create a super new strain that could be better than both of them, and therefore, we need to be looking for these hybrid viruses, as they will pop up in the future.” In the event of a super variant, he said, asking vaccine companies to adjust their vaccines to give the people the immunity that is needed to protect against such super variants is the option, adding that it should be possible.  With regard to dealing with new variants, he said: “Vaccines reduce the severity of the disease. The chances of you dying if you have been vaccinated are many, many times reduced. So it is much better to get the vaccine than it is to get the real virus because you could die. So you can still get the virus even if you are double vaccinated, but you have got less of a chance of getting it and you are going to be less ill and you have got less of a chance of passing it on.”  Meanwhile, certain Covid-19 management authorities of India have called what they see in the West a “Delmicron” wave. As quoted by Times of India, Maharashtra Covid-19 Task Force member Shashank Joshi had said: “Delmicron, the twin spikes of Delta and Omicron, in Europe and the US, has led to a mini tsunami of cases.” Recombination events For a combined variant of the virus to emerge, a person must be infected with two strains of the coronavirus – likely from two separate sources – at the same time, and then the viruses must bump into each other inside the body.  Once the viruses are inside the body, the way they spread is by forcing human cells to make more of them. The coronavirus is made up of genetic material called ribonucleic acid (RNA) and, to reproduce, it must force the body to read this RNA and make exact copies of it. There are inevitably errors when this happens because it happens so fast and so often and also because natural processes are imperfect. If two viruses are in the same place at once, both being duplicated by the same cells, there is a chance the RNA genes could be mixed up, just as there could be a mix-up.  Daily Mail further noted: “Most places have dominant variants of the virus, and therefore, someone getting infected with two is unlikely to begin with. For healthy people, there is likely only a window of around two weeks before the body starts to develop immunity and successfully clear out the first version of the virus. This risk window could be cut to days for the majority of the people who develop Covid-19 symptoms – which takes an average of five days – and then stay at home sick. But, huge, poorly controlled outbreaks like the ones in the UK and US over the winter, significantly raise the risk of combination events simply because the number of infections is higher.” With regard to the Covid-19 pandemic, recombination events have been a topic of discussion from the beginning, even though they were not discussed as much due to the low level of threat they posed. Scientists say that recombination events are likely to have played an important role in the virus that caused Covid-19 to emerge as a human pathogen, and that such events that were reported during the Covid-19 pandemic had not created strains which are strong enough to beat the Alpha (B.1.1.7) and especially Delta variants. In a study published in July 2020, several researchers at the Los Alamos National Laboratory had reported that a portion of the receptor-binding domain of the SARS-CoV-2’s spike protein (the part of the spike that directly interacts with the receptor known as ACE2 that the virus uses to gain entry into cells) came from recombination with pangolin coronaviruses. The Scientist quoted one of the researchers Bette Korber as having said: “It (viruses recombining) should be happening because it is a very important evolutionary mechanism for these viruses. At the same time, quantifying how much it is there can be tricky, because...it is computationally not easy to look at vast data sets.”  Scientific experiments have shown that the swapping of genes between two viruses/variants, or recombination, could result in a more dangerous virus/variant than the two parent viruses/variants, and that it can happen in various viruses including human immunodeficiency virus (HIV) and influenza. One of the most notable experiments in this regard is the one pertaining to H1N1 (the virus that caused several pandemics, the latest being the 2009 swine flu pandemic) and H9N2 (a subtype of the Influenza A virus, which causes bird flu) flu viruses. In 2011, a group of Chinese researchers said that the H1N1 flu virus could create a more virulent virus/strain if it swapped genes with a bird flu virus that was circulating in poultry.  In a research published in the journal Proceedings of the National Academy of Sciences of the US (PNAS), it was stated that a team of scientists, led by Jinhua Liu of the China Agricultural University in Beijing, had used laboratory techniques to create viruses with different combinations of genes obtained from the H9N2 virus and H1N1 virus. Out of 73 different combinations, when tested on mice, eight had been found to be more dangerous than the parental viruses/strains. Theories and possibilities The reason a number of countries have expressed concerns about the possibility of the development of a super variant is due to the Delta and Omicron variants becoming the dominant variants in many parts of the world, over the previously identified other variants.  As far as the ability to cause severe complications and symptoms and also transmissibility is concerned, the Delta variant was known as the most dangerous variant before the Omicron variant emerged. However, scientists project that the Omicron variant will eventually surpass the Delta variant, and will soon become the dominant variant in Europe and in a number of other parts of the world. According to British media reports, the Omicron variant is already dominant in London just two weeks after being spotted in the UK, and experts estimate that it will be the main strain by the new year. This week, it was also reported that the Omicron variant has become the dominant variant in the US. It is in such a context that scientists fear that the two most dominant and aggressive variants will create a super variant. While the scientific community remains divided as far as the emergence of a more dangerous super variant coming into existence as a result of the Delta and Omicron variants combining, is concerned, based on the available data and theories, scientists point out that theoretically, the emergence of such a variant cannot be ruled out and that it is not at all impossible.  Arguments against these theories, however, say that the theoretical possibility is not adequate to reach a conclusion, and that even though a super variant could be created, the chances of it happening are extremely low given the nature of Covid-19 and successful vaccination throughout the world. One of the reasons they point out is that some places already have dominant variants, which in turn lowers the possibility of getting infected by two variants at once. In addition, some researchers have pointed out that the discussion on the emergence of a super variant should be based on whether the vaccines that are currently in use can prevent a super variant infection or health complications caused by such a variant. They argue that a super variant, despite how transmissible, would not be an issue if the vaccines are effective against them, and that therefore, studies should focus on how a super variant reacts to the vaccines. Whether a super variant has already been created by the Delta and Omicron variants and how such a variant can be dealt with, are ongoing discussions and there is no one answer to these questions other than for theoretical possibilities. While vaccination is still the best solution to prevent deaths and severe complications or symptoms due to Covid-19, as White stated, scientists predict that vaccines may also have to be adjusted to deal with newer, more aggressive variants. Although many Covid-19 vaccines are still being tested, medical experts recommend vaccination for the variants that have been identified so far, and even though there is no assurance, in most cases, vaccination has been effective in protecting against Covid-19. In the case of the said super variant too, being vaccinated could be beneficial.