Abigail Banerji26 Feb 2021 09:17:26 IST
With ‘Ms Rona’, better known as the coronavirus, celebrating her first birthday since she came into our lives, terms like the pandemic, PPE, antibodies, antigens, etc. Became popular and is now part of our daily vocabulary. Many of us may now understand the complex process of developing a vaccine, the clinical trials it undergoes, and the approvals required by the regulations before it is rolled out. We lived and we learned.
With the SARS-CoV-2 virus rapidly ‘mutating’, new ‘variants’ of the virus have emerged in many parts of the world. In the pre-COVID-19 era, we may have used this new piece of information to impress friends or family during dinners or cocktails. But let’s be honest, it’s unlikely that the different variants could make this happen anytime soon.
Let us then dive the deepest and understand the basics …
What is a virus?
Before the COVID-19 pandemic, we vaguely heard of viruses that spread diseases such as Ebola in Guinea and Congo, swine flu or bird flu in India and Russia, AIDS, and so on. Cause. We now know that the SARS-CoV-2 virus COVID causes -19 disease.
According to a report by Scientific American, the scientific community has debated for years the definition of a virus; first as poison, then life form and then biological.
Today, viruses are considered somewhere between a living and a non-living thing.
A virus consists of a nucleus of genetic material (DNA or RNA) surrounded by a protective layer of protein. They can cling to host cells and use the machinery of the host cell to multiply the genetic material. Once this replication process is complete, the virus leaves the host by budding or bursting from the cell and destroying it in the process.
Viruses cannot repeat on their own, but once attached to a host cell, they can thrive and influence the behavior of the host cell in a way that damages the host and benefits the virus.
What is a tension?
According to a report in The conversation, is a variant that is constructed differently, shows clear physical characteristics and acts differently from the parent virus. These behavioral differences can be subtle or obvious.
Coronaviruses, such as the severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), are infested with protein “nails” that attach with receptors to the cells of their victims. The SARS-CoV-2 is now one of a handful of other known strains in the coronavirus family, including the SARS and MERS viruses.
Experts believe the term strain is often misused.
“There is one strain of coronavirus. It is SARS-CoV-2. It is the single strain, and there are variants of the strain,” The Independent quoted Professor Tom Connor of the School of Biosciences at Cardiff University.
What is a mutation?
A virus consists of a series of DNA or RNA, which is basically a string of nucleotide letters that encode genes in all living things. Any change in these letters is called a mutation and occurs when a virus sequence repeats itself. Mutations occur very randomly in a virus – a fact that can work for or against us in a pandemic scenario. A mutation can be beneficial to the virus and make it stronger, or it can be harmful and reduce its virulence.
Unlike the flu virus, SARS-COV-2 contains a protein known as a proofreading enzyme. The enzyme is similar to what a copy editor in a newspaper does, that is, to look for spelling errors on a page. This enzyme will make corrections based on the source virus sequence. So if there have been changes due to a random mutation, it will try to correct it.
Just like an editor of human copies, a mutation will sometimes pass and remain the proofreading enzyme. As the mutant virus particle repeats, its entire genome, including the site of the mutation, is duplicated and transmitted by future generations of the virus.
So how does one know if the virus has mutated? This is where a virologist comes in. Virologists have worked tirelessly to sequence all the variants that infect humans. The original virus, found in Wuhan, is used to compare the mutation of the coronavirus variants.
What is a variant?
Simply put, “a variant is a version of the virus that accumulates enough mutations to represent a separate branch in the family tree,” say dr. Amesh Adalja, senior expert at the Johns Hopkins Center for Health Safety.
Every mutation and strain of a virus is a variant, but every variant is not a strain.
Most variants are no cause for concern. This is because the mutations did not drastically change the virus in question. However, when a lot of mutations have occurred, it can sometimes affect the way the virus acts, spreads or infects. This is when a variant becomes a ‘variant of concern’. A classic example is the new variants spread through parts of the UK, Africa and Brazil.
Scientists are closely monitoring the variants of SARS-CoV-2 to understand how genetic changes to the virus can affect its contagion (and thus its spread), the severity of the disease, its treatment and the effectiveness of the available vaccines. . say Dr. Thomas Russo, Professor and Head of Infectious Diseases at the University of Buffalo in New York.
What are the new variants in circulation?
A variant of SARS-CoV-2, known as B.1.1.7, has been circulating in the UK since December 2020 and now cases are appearing all over the world. Scientists have found evidence that this variant has an increased risk of death compared to other variants.
An infographic that talks about all the latest SARS-CoV-2 variants being distributed. Image Credit: European Center for Disease Prevention and Control
In South Africa, another variant of SARS-CoV-2, known as B.1.351, has emerged. It has some similarities with the UK variant and can also re-infect people who have recovered from other COVID-10 variants. There is also evidence that the vaccine AstraZeneca and Moderna are not as effective against this variant.
A variant known as P.1 originated in Brazil and was first discovered in humans travel from the South American country to Japan. There is evidence to suggest that this variant may affect the way antibodies respond to the virus. The mutation of the P.1 variant prevents the antibodies from recognizing and neutralizing the virus.
According to the CDC, all three variants share one specific mutation called D614G which allows it to spread faster.
As new variants are constantly emerging, it is important that we are at the top of our genome sequence game. By doing so, we will be able to find new variants that are of public health concern (as they may be more contagious, cause serious illness, develop a vaccine or immune resistance), and we can get them in advance. If you ignore these emerging new mutations, they can not disappear and can be detrimental to us in the long run.