SARS-CoV-2 variant, strain and mutation all mean different things – tech news, Firstpost

Abigail BanerjiFeb 26, 2021 9:17:26 AM EST

With ‘Ms. Rona’, better known as the coronavirus, celebrating her first birthday since entering our lives, terms like pandemic, PPE, antibodies, antigens, etc. have grown in demand and popularity, and are 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 regulatory approvals it would need before its deployment. We have lived and we have learned.

With the rapidly “mutating” SARS-CoV-2 virus, new “variants” of the virus have appeared 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 a dinner party or cocktail party. But let’s be honest, the very variants in question probably won’t let that happen anytime soon.

Next, let’s go over and understand the basics …

What is a virus?

Before the COVID-19 pandemic, we had vaguely heard of viruses causing diseases like Ebola in Guinea and Congo, swine flu or bird flu in India and Russia, AIDS, etc. The SARS-CoV-2 virus is now known to cause COVID -19 disease.

According to a report by American scientist, the scientific community has debated for many years the definition of a virus; first as a poison, then a life form, and then a biological chemical.

Today viruses are considered to fall somewhere between a living and a non-living being.

A virus consists of a nucleus of genetic material (DNA or RNA) surrounded by a protective layer of proteins. They can attach themselves to host cells and use the host cell’s machinery to multiply its genetic material. Once this replication process is complete, the virus leaves the host by budding or bursting out of the cell, destroying it in the process.

Viruses cannot replicate on their own, but once they attach to a host cell, they can thrive and affect the behavior of the host cell in a way that damages the host and benefits the virus. .

What is a strain?

A strain, according to a report in The 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 the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), are dotted with “spikes” of proteins that attach to receptors on the cells of their victims. SARS-CoV-2 is now one of a handful of other well-known strains of 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 unique strain, and there are variants of this 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 essentially a string of nucleotide letters encoding the genes of all living things. Any change in these letters is called a mutation and occurs when a viral sequence replicates. Mutations happen very randomly in a virus – a fact that might work for or against us in a pandemic scenario. A mutation can benefit the virus and make it stronger, or it can be harmful and reduce its virulence.

SARS-COV-2, unlike the influenza virus, has a protein known as a proofread enzyme. The enzyme is similar to what a copy editor does in a journal, that is, to check for spelling errors on a page. This enzyme will make corrections based on the sequence of the original virus. So if there were any changes that took place due to a random mutation, it will try to correct them.

Much like a human copy editor, sometimes a mutation will pass the proofread enzyme and stay. As the mutant viral particle replicates, its entire genome, including the site of the mutation, is duplicated and passed on by future generations of the virus.

So how do you know if the virus has mutated? This is where a virologist comes in. Virologists have worked tirelessly to sequence all of the variants that infect people. The original virus, found in Wuhan, is used to compare itself to mutating coronavirus variants.

What is a variant?

Simply put, “a variant is a version of the virus that has accumulated enough mutations to represent a distinct branch of the family tree”, said infectious disease expert Dr Amesh Adalja, principal investigator at Johns Hopkins Center for Health Security.

Every mutation and strain of a virus is a variant, but every variant is not a strain.

Most of the variations are not of concern. Indeed, the mutations did not bring any radical change to the virus in question. However, when a cluster of mutations occurs, it can sometimes affect the way the virus behaves, spreads, or infects people. This is when a variant becomes a “variant of concern”. The new variants that are spreading in parts of the UK, Africa and Brazil are a classic example.

Scientists are closely monitoring variants of SARS-CoV-2 to understand how genetic changes in the virus might impact its infectivity (and therefore, its spread), disease severity, treatment, and efficacy. vaccines available, said Dr Thomas Russo, professor and chief 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 spread across the UK since December 2020 and now cases are on the rise worldwide. Scientists have found evidence that this variant has an increased risk of death compared to other variants.

In South Africa, another variant of SARS-CoV-2 known as B.1.351 has emerged. It has some similarities 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 is not as effective against this variant.

A variant known as P.1 appeared in Brazil and was first discovered in humans traveling from the South American country to Japan. Some evidence suggests that this variant may affect the way antibodies react with the virus. The mutation of the P.1 variant prevents antibodies from recognizing and neutralizing the virus.

According to CDC, these three variants share a specific mutation called D614G that allows it to spread faster.

With new variants constantly emerging, it’s important that we are on top of our genome sequencing game. By doing this, we can find new variants of public health concern (because they could be more infectious, cause more serious disease, develop a vaccine or immune resistance) and we can get ahead. However, ignoring these new emerging mutations will not make them go away and can be detrimental to us in the long run.