Highlights
- Mutations increase the ability of virus to infect cells: Experts
- Mutation in the spike protein governs entry into human cells: Dr. Aggarwal
- A standard RT-PCR Test can detect COVID-19 but not the type of strain
New Delhi: With the vaccine programmes for COVID-19 being rolled out in several countries including the United Kingdom (UK) and many others like India gearing up for it, the emergence of a new strain of the mutated coronavirus in the UK and in South Africa has raised an alarm among people globally. The new variants caused by mutation of the SARS-CoV-2 virus, which is responsible for COVID-19 pandemic, is said to be up to 70 per cent more transmissible than the original. While it is not more dangerous than the original virus, it has also been linked with the exponential rise in the number of infected cases in both the respective countries. According to the World Health Organisation (WHO), while the new strains in UK and South Africa have emerged at the same time, both are different. The UK variant has been detected in few other countries as well including India. Here is what is known, so far, about the new strains of coronavirus.
Also Read: New COVID-19 Strain Could Have Entered India Prior To December, Says AIIMS Director
What Is Mutation And How Has The Coronavirus Mutated?
According to Dr. Preeti Kumar, Vice President, Public Health System Support at the Public Health Foundation of India, mutation is a natural process that occurs when a virus multiplies. It refers to the error in the copying mechanism of the biological systems because of which the genetic sequence of a virus changes slightly. The virus that multiplies through DNA (Deoxyribonucleic acid), the genetic sequence is copied into another DNA molecule almost accurately. However, among viruses like coronavirus that multiply by copying RNA (Ribonucleic acid), chances of errors are more as the replication machinery does not have the correction capabilities. These errors in the genetic material lead to mutation.
The World Health Organisation (WHO) says that all viruses including the SARS-CoV-2, change over time, but the majority of the mutations or changes do not have a direct benefit to the virus or may even be detrimental to its propagation. There have been several mutations of the novel coronavirus till now, says WHO.
According to Dr KK Aggarwal, President at Confederation of Medical Associations of Asia and Oceania, Heart Care Foundation of India, the existing dominant strain of the mutated coronavirus is called D614G which swaps between amino acids D and G. Amino Acids are organic compounds that combine to form proteins. In coronavirus, these proteins are found in the spikes of the receptor of the virus that helps in binding the virus with host cells. Receptors in the virus produce an immune response in the host body.
The original strain of the coronavirus had emerged with amino acids of ‘S’ type which mutated into ‘L’ type, he further added. While the ‘L’ type strain of coronavirus became more dominant in China, the ‘S’ type coronavirus became more contagious in the rest of the world. In India, the first strain of coronavirus was ‘L’ strain that originated in Wuhan, according to Dr Aggarwal, which eventually mutated into ‘S’ and ‘G’ stains, which have spread across the country.
Also Read: Scientists Quell Concerns On New COVID-19 Variant, Say Staying Cautious Sufficient
What Is The New Strain?
The new UK variant is referred to as SARS-CoV-2 VUI 202012/01 (Variant Under Investigation, year 2020, month 12, variant 01). The authorities of the UK officially reported this variant on December 14. It was first detected in September through whole-genome sequencing of the virus. Genome sequencing is the process of determining the complete DNA sequence of an organism’s genome which refers to its all genetic material.
Dr. Aggarwal said that the newly identified UK variant is a result of mutation in the spike N501Y of the SARS-CoV-2 which is a key part of a virus that helps it to gain entry into cells and lead to infection.
According to Dr Emma Hodcraft, Molecular Epidemiologist at the University of Basel in Switzerland, who has been studying both the UK and South African strains in detail, both variants share the same mutation in spike N501Y, but they have many separate mutations as well. While the new UK variant has been identified in several countries including Australia, Denmark, Italy, Iceland and the Netherlands, the South African variant, known as 501.V2, has been reported in South Africa only, so far, she added.
Is the new UK variant the same as the new South African variant (501Y.V2)?
No.
They both share the same mutation in spike: N501Y (N->Y at position 501). However, the 2 variants have arisen separately.
1/Nhttps://t.co/m4sx1YN7dO pic.twitter.com/N1Zmyso4mh
— Dr Emma Hodcroft (@firefoxx66) December 19, 2020
The new South African strain is also very contagious and has been causing a lot of cases and hospitalisations. Dr. Aggarwal said that the new strain in South Africa is more concerning than the UK one, in terms of clinical outcome.
Also Read: Non-judicious Use Of Therapies For COVID-19 Leads To Virus Mutations: ICMR Chief
Where Has The New Strain Come From?
Dr Ravindra Gupta, Professor of Clinical Microbiology at the University of Cambridge said that the new variant is unusually highly mutated as almost 17 mutations have occurred on the same virus. He said,
The most likely explanation for this is that the variant has emerged in a patient who has been carrying the virus for a long period of time.
He further said that one of the conditions for coronavirus mutations is using the convalescent plasma therapy to treat COVID-19 patients. He said,
If you use plasma or antibody therapy on somebody with poor immune function, then the virus is fighting against only one kind of antibody that has been injected in the patient. This antibody probably may not be all of the places where the virus is dividing or making copies. So, we do need to be careful while using therapies like these in people with very poor immune function and they should be kept in isolation with regular testing and sequencing of the virus to ensure that the muta{tions are not emerging.
Dr Aggarwal says that infected persons with a weakened immune system that is unable to beat the virus, is breeding ground for the virus to mutate.
The Mutant Virus Spreads 70 Per Cent More Transmiaaible Than The Existing Virus But Is Not More Fatal
The initial analysis of the stain indicates that the new variant may spread more rapidly between people but it is not worsening the disease and is not more deadly than the existing strain. The WHO said that experiments are still ongoing to investigate if the new variant can cause any changes in the severity of symptoms or antibody generation. Thus it is too early to say how fatal it is, say experts.
According to Dr. Aggarwal, since the new strains are almost 70 per cent more contagious, the Reproduction(R) number will rise. R number represents the number of people an infected person is passing the infection to and is a key factor in gauging the coronavirus pandemic. R number for a disease should remain below 1, as per experts.
Dr. Aggarwal said that due to the new strain, R is expected to increase in the UK by 0.4, bringing it to a range of 1.5 to 1.7. This means that if infected people were previously infecting 1.1 persons each on an average, they will now infect 1.5 persons each.
While talking about the contagious new variant, Dr Chand Nagpaul, the Chair of the British Medical Association’s Council said that this increase in the rate of transmission makes managing the pandemic even more challenging. He highlighted that in the UK, about 90 per cent of capacity of all hospital beds is presently occupied, on account of the new strain of the virus. He stressed on continuing the implementation of preventive measures to contain the transmission and said that the lockdown in the UK may be stretched for a while. He suggested ramping up vaccinating patients on priority to fight the virus strain.
A Standard RT-PCR Test Cannot Identify The Type Of Strain
Dr Rakesh Mishra, director of the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, highlighted that while the RT-PCR (Reverse transcription-polymerase chain reaction) test, which is considered better and the rapid antigen and antibody tests, can detect presence coronavirus, it does not have the ability to identify the type of strain present. He said that only whole-genome sequencing of the virus can detect the strain which can help in determining how widespread and dominant the new strain is. For this, the samples that are COVID-19 positive are taken to the sequencing lab where the sequence of the genome is determined which can pick up even a very small change in the virus, he said. These changes characterise the new variants.
WHO advises all countries to increase the routine sequencing of SARS-CoV-2 viruses where possible and share the data with internationally to help identify the same strain in other countries. This, as per WHO, will help in scientific collaborations in order to contain and fight the strain.
Experts Believe That, As Of Now, Vaccines Will Be Effective Against The New Variants As Well
As of now, the new variant does not cause any change in the response of the body’s immune system to the vaccines available or those being developed, particularly in India, said Dr V K Paul, Member- Health, NITI (National Institution for Transforming India) Aayog during a press briefing on Tuesday.
In a statement, German pharmaceutical company BioNTech which has developed a COVID-19 vaccine in collaboration with USA based Pfizer said that it is confident that its coronavirus vaccine works against the new UK variant, but further studies are needed to be completely sure. Pfizer-BioNTech’s COVID-19 vaccines have got emergency use approval in a few countries including the UK and the USA.
According to Dr. Mishra, the vaccines built by Pfizer-BioNTech or Moderna are mRNA (messenger RNA) based vaccines target one particular protein (spike protein in the case of SARS-CoV-2 virus) and the change that has happened in the mutated virus is very small which will not affect the efficiency of the vaccine. He added that vaccines trigger the immune system to generate multiple antibodies against the same protein and the multiple kinds of viral proteins are recognised by the immune system through the antibodies. In the case of other vaccines, like the ones that are being made domestically in India like Bharat Biotech’s Covaxin or AstraZeneca-Oxford’s vaccine which is being manufactured as Covishield by the Pune based Serum Institute of India, the whole virus is targeted and not just one protein. Therefore, these vaccines are not at all going to be affected by the mutations as these are targeting multiple proteins of the virus, said Dr. Mishra.
No Matter Which Variant Of Coronavirus Dominates, The Public Health Response Needs To Be The Same: Experts
While the countries need to assess their type of strain and the level of transmission, they must continue implementing preventive measures irrespective of the coronavirus variant present, say experts. These measures include following physical distancing, frequent handwashing, wearing face masks, avoid non-essential travelling, contact tracing, quarantining, isolating among others along with enhancing medical facilities and adapting healthcare response as per the guidelines of the health authorities.
NDTV – Dettol Banega Swasth India campaign is an extension of the five-year-old Banega Swachh India initiative helmed by Campaign Ambassador Amitabh Bachchan. It aims to spread awareness about critical health issues facing the country. In wake of the current COVID-19 pandemic, the need for WASH (Water, Sanitation and Hygiene) is reaffirmed as handwashing is one of the ways to prevent Coronavirus infection and other diseases. The campaign highlights the importance of nutrition and healthcare for women and children to prevent maternal and child mortality, fight malnutrition, stunting, wasting, anaemia and disease prevention through vaccines. Importance of programmes like Public Distribution System (PDS), Mid-day Meal Scheme, POSHAN Abhiyan and the role of Aganwadis and ASHA workers are also covered. Only a Swachh or clean India where toilets are used and open defecation free (ODF) status achieved as part of the Swachh Bharat Abhiyan launched by Prime Minister Narendra Modi in 2014, can eradicate diseases like diahorrea and become a Swasth or healthy India. The campaign will continue to cover issues like air pollution, waste management, plastic ban, manual scavenging and sanitation workers and menstrual hygiene.
