Abigail BanerjiFebruary 26, 2021 9:17:26 AM IT IS
With “Ms Rona”, better known as coronavirus, which celebrates her first birthday since she came into our lives, terms such as pandemic, EPP, antibodies, antigens, etc. they have grown in demand and popularity, and are now part of their daily vocabulary. Many of us could now understand the complex process of a developing vaccine, the clinical trials it goes through, and the regulatory approvals it would need before it was launched. I lived and learned.
With the rapidly “mutant” SARS-CoV-2 virus, new “variants” of the virus have emerged in many parts of the world. In the pre-COVID-19 era, we could have used this new slice of information to impress friends or family at dinner or cocktails. But let’s be honest, it is very unlikely that the variants in question will let this happen soon.
Then we dive deep and understand the basics …
What is a virus?
Before the COVID-19 pandemic, I had vaguely heard of viruses that cause diseases such as Ebola in Guinea and Congo, swine flu or bird flu in India and Russia, AIDS, etc. We now know that the SARS-CoV-2 virus causes COVID-19 disease.
According to a report by Scientific American, the scientific community has been debating the definition of a virus for many years; first as a poison, then as a life form, and then as a biological chemical.
Today, viruses are considered to be somewhere between a living thing and a non-living thing.
A virus it consists of a core of genetic material (DNA or RNA) surrounded by a protective layer of proteins. They can attach to host cells and use host cell machinery to multiply their genetic material. Once this replication process is complete, the virus leaves the host either by budding or bursting from the cell, destroying it in the process.
Viruses cannot replicate on their own, but once attached to a host cell, they can thrive and affect the behavior of the host cell in a way that harms the host and benefits from the virus.
What is a strain?
A strain, according to a report from Conversation, is a variant that is constructed differently, has distinct physical properties and behaves differently from its parent virus. These differences in behavior can be subtle or obvious.
Coronaviruses, such as severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2), are studded with protein “tips” that attach to receptors on their victims’ cells. SARS-CoV-2 is now one of a handful of other well-known strains in the coronavirus family, including SARS and MERS.
Experts believe that the term strain is often misused.
“There is a strain of coronavirus. I mean SARS-CoV-2. This is the only strain and there are variants of that strain.” The independent quoted Professor Tom Connor of the School of Biosciences at Cardiff University.
What is a mutation?
A virus is made up of a sequence of DNA or RNA, which are basically a string of nucleotides encoding genes from all living things. Any change in these letters is called a mutation and occurs when a virus sequence reproduces itself. Mutations occur very randomly in a virus – which could work for or against us in a pandemic scenario. A mutation can be beneficial for the virus and make it stronger or it can be harmful and reduce its virulence.
SARS-VOC-2, unlike influenza virus, has a protein known as a corrective enzyme. The enzyme is similar to what a children’s editor does in a newspaper, that is, to check for spelling errors on a page. This enzyme will make corrections based on the sequence of the virus of origin. So if there have been changes that have occurred due to a random mutation, it will try to correct them.
Like a human children’s editor, sometimes a mutation passes over the correction enzyme and remains. As the mutant virus particle replicates, its entire genome, including the site of mutation, is duplicated and transported by future generations of the virus.
So how do you know if the virus has moved? This is where a virologist comes in. Virologists have worked tirelessly to sequence all variants that infect humans. The original virus, found in Wuhan, is used to compare mutant coronavirus variants.
What is a variant?
Quite simply, “a variant is a version of the virus that has accumulated enough mutations to represent a separate branch on the family tree.” say infectious disease expert Dr. Amesh Adalja senior scientist at the Johns Hopkins Center for Health Security.
Every mutation and strain of a virus is a variant, but every variant is not a strain.
Most options are not a cause for concern. This is because the mutations did not make any drastic changes to the virus in question. However, when a lot of mutations have occurred, it can sometimes affect how the virus behaves, spreads, or infects people. Then a variant becomes a “variant of concern”. A classic example is the new variants that are spreading through parts of the United Kingdom, Africa and Brazil.
Scientists are closely monitoring SARS-CoV-2 variants to understand how genetic changes in the virus could affect its infectivity (and therefore its spread), the severity of the disease, the treatment and the effectiveness of available vaccines, say Dr. Thomas Russo, professor and head of infectious diseases at Buffalo University in New York.
What are the new variants in circulation?
A variant of SARS-CoV-2 known as B.1.1.7 has spread in the UK since December 2020, and cases are now occurring worldwide. Scientists have found some 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 that are spreading. 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 bears some resemblance to the UK variant and may also re-infect people who have recovered from other COVID-10 variants. There is also some evidence that the AstraZeneca and Moderna vaccine are not as effective against this variant.
A variant known as P.1 appeared in Brazil and was first discovered in humans traveler from the South American country to Japan. There is some evidence to suggest that this variant may affect how antibodies react to the virus. The P.1 mutation stops the antibodies from recognizing and neutralizing the virus.
In accordance with CDC, all three of these variants share a specific mutation called D614G that allows it to spread faster.
With new and evolving variants, it is important that we are at the top of our genome sequencing game. By doing this, we will be able to find new variants that are of interest to public health (because they could be more infectious, can cause more severe diseases, develop a vaccine or immune resistance) and we can overcome this. However, ignoring these new emerging mutations will not make them go away and may be to our detriment in the long run.