translated from Spanish: Coronavirus: what is the difference between mutations, variants and a strain

With confirmation in several countries that have recorded the variant of SARS-CoV-2 that has wreaked havoc in the UNITED Kingdom, confusion has also arisen regarding the terms used to refer to it.

Is it correct to say it’s a new strain? Is a mutation equal to a variant? What is a lineage?

Before detailing what each term refers to, we first remind you that, as experts have explained to us, all viruses constantly mutate, at different rates and with different repercussions.

On variant B.1.1.7, reported by the UNITED Kingdom in December, reports have been concerned that it may be up to 50% more contagious.
However, so far there is no scientific evidence that it causes further harm in COVID-19 patients or makes the virus more lethal. Nor can it affect the effectiveness of vaccines developed so far.

Mutations create variants or lineages

As contagions occur, ‘errors’ occur in copying and then mutations or changes occur in the genetic code of viruses, such as that caused by COVID-19.

When performing genetic sequencing or analysis of the virus, from samples taken in different regions of the world, it is that scientists identify certain characteristics by which such mutations can be grouped into variants or lineages.

A different mutation of coronavirus was detected in the United Kingdom. Pa

For the analysis, phylogenetic trees are created, which are like family trees in which all relatives who detach from viruses such as SARS-CoV-2 are expressed.

Each branch that arises directly from SARS-CoV-2 are called lineages, which are designated with a series of numbers and a letter from the alphabet, to identify them, considering their order of appearance and their genetic composition.

The B.1.1.7 lineage has different mutations in its genome, so far about 23, but the main one is the one that develops at position 501 of its genetic code, where the amino acid asparagin (N) has been replaced by tyrosine (Y).

The abbreviation for this mutation is N501Y, which is also sometimes referred to as S:N501Y, to specify that it is in the spike (or peak) protein of the virus.

It is correct to say, then, that the variant or lineage B.1.1.7 arrived in Mexico.

In addition to the UK variant, scientists identified the 501Y variant in South Africa. V2.

We don’t want to confuse you, but one detail is that both the UK and South Africa variant share a mutation, that of position 501.

In the United States, so far, 72 cases of variant B.1.1.7 have been confirmed, according to the Centers for Disease Control and Prevention (CDC).

POLITICAL ANIMAL

So what is a strain?

To understand this, we can mention at the outsteo that SARS-CoV-2 is one of the different strains of coronaviruses.

The two most well-known types or strains of coronavirus so far are: SARS-CoV-2 found in Wuhan, China, since late 2019.

And before SARS-CoV, which causes severe acute respiratory syndrome or SARS. Then: each of the new types or species of coronavirus is called a strain.

It is vague to say that the variant registered in the UK is either a new one, or to mention that a new strain arrived.

For that to happen, the virus would have to undergo a drastic change or mutation in its genetic chain, which has not happened so far.

Hence, at the moment it is still considered that the vaccines developed so far are still useful to deal with the virus, and to avoid more cases of deaths by Covid-19.

“There is a strain of coronavirus. That’s Sars-Cov-2. That’s the only strain and there are variants of that strain. These are variants,” he said of B.1.1.7. in December to the British newspaper “The Independent” Professor Tom Connor, of the School of Biosciences of Cardiff University.

Original source in Spanish