Tutorial for New Parents on Variants’ Names: What’s with All of the Greek Letters?

  • 2
    Shares

Being a new parent, or an expectant parent can make you particularly aware of health issues, especially during the pandemic that we have endured over the past year and a half. During all that time, terminology has evolved, including with respect to the clinically important variants of SARS-CoV2 (the virus that causes COVID-19) that you are hearing discussed on the news. Months ago, you heard a lot about variants named for different countries, states, or cities. Those variants also had numbers, like B.1.1.7 and B.1.351. Now you’re hearing Greek letters, like alpha (α) and delta (δ), which is a big development. Just as in space exploration, where NASA’s selection of the Greek goddess Artemis, sister of Apollo, as the name of the program to bring astronauts back to the Moon in the next few years means that it’s serious, the World Health Organization (WHO) applying Greek letters to variants of SARS-CoV2 means that we’ll be dealing with such variants for a long time.

We’ll get into what the new designations mean shortly, but first let’s discuss something more basic, namely what is a variant, and how is that different from a strain? Being on the boundary between non-living and living entities, viruses must utilize the machinery of cells that they infect in order to reproduce, but they carry their own genetic instructions, in the form of either DNA or RNA. In the case of SARS-CoV2, as with all coronaviruses, the viral genome (the collection of genetic instructions) consist of a molecule of RNA. Two viruses that vary in their sequence of RNA or DNA building blocks are called variants of one another. The variants of SARS-CoV2 that have been discussed on the news are called variants, because their sequences of RNA building blocks differ from those of what have been called the wild type SARS-CoV2 variants, the variants of SARS-Cov2 that began spreading out from Wuhan, China in early 2020, but those variants themselves were variants from still another SARS-CoV2 virus. When we talk about variants of a virus, we are referring to variations on what scientists call the genotype of the virus, meaning purely the content of the genetic instructions. However, when a variant, on account of its varying genetic sequence, exhibits unequivocal changes in behavior from the wild type —what scientists call phenotypic changes— such a variant is called a strain. You may hear journalists and some people in the government use the terms variant and strain interchangeably. Technically, however, the various manifestations of SARS-CoV2 that differ from the virus that we were dealing with when it spread from Wuhan in early 2020, are being called merely variants, because the behavior of the known variants hasn’t been dramatically different from the behavior of the wild type viruses to deserve the designation of strain, so far. They basically all cause the same disease —COVID-19— although there are some emerging indications that at least one variant may possibly cause COVID-19 with some features that were not seen in most other COVID-19. However, on account of their varying RNA sequences exhibiting a tendency to spread more easily from human to human —becoming more infections to the point that we might consider calling some of them strains— several of the variants are being called variants of interest.

Here are the main variants of interest that you may have heard discussed in the news with a Greek letter naming convention issued by the WHO:

The Alpha (α) variant: This is the SARS-CoV2 variant that we have discussed several times on The Pulse as variant B.1.1.7. Since it emerged in the United Kingdom, it has been known informally as the “UK variant”. However, one of the reasons for the WHO naming convention is to avoid stigmas that may be associated with naming variants for particular cities, states, or geographic regions. In many locations on Earth, including in North America and the UK, variant Alpha is now the standard variant causing COVID-19. Being even more contagious (having a higher R0 value) than the “wild type” variant that was causing most COVID-19 when it spread around the planet last year, Alpha took over; in the UK, it now accounts for 95 percent of SARS-CoV2 infections Although Alpha spreads more aggressively than the wild type, the resulting disease is the same as that caused by the wild types, and the approved vaccines protect just about as well against the Alpha variant as against the wild types. Consequently, the only people who are at elevated danger, due to the Alpha variant, are the unvaccinated. So get your jabs, if you have not done so yet.

The Beta (β) variant: This is the B.1.351 variant, known informally as the South African variant. Like the Alpha variant, the Beta variant is more contagious (it spreads faster) than earlier variants. Variants result from an accumulation of mutations, changes within the sequence of building blocks of the viral RNA. In the case of the Beta variant, scientists are particularly concerned about one of the mutations causing the variance, because it could eventually lead to what is called “escape” from the immune system response. Despite this possibility, the currently approved vaccines provide protection against variant Beta, especially protection against severe disease and death. So get your jabs, if you have not done so yet.

The Gamma (γ) variant: This is the P.1 variant, known informally as the Brazilian variant. Like Alpha and Beta, this variant spreads more quickly than earlier variants. This has led to widespread COVID-19 disease in and around the Amazonian city of Manaus. As with the Beta variant, because of the particulars of the underlying mutations, there is concern that the Gamma variant can evolve into an escape variant. Despite this possibility, the currently approved vaccines provide protection against variant Beta, especially protection against severe disease and death. So get your jabs, if you have not done so yet.

The Delta (δ) variant: This is the B.1.617.2 variant, known informally as the Indian variant. While it is indeed the most commonly reported variant in India, Delta has been spreading to, and within, many other countries. As with Beta and Gamma, there is concern that it may evolve to escape the immune response. Laboratory studies have revealed Delta is 6.8 times more resistant to neutralization by antibodies that are made in response to the Pfizer-BionTech and Moderna vaccines, compared with the earlier variants that were the basis of those vaccines. The vaccines still provide significant protection anyway, because the neutralization against the earlier variants is very strong in the first place, and because the immune system also produces what scientists call a T cell (T lymphocyte) response that has not yet been fully characterized. As with Alpha, Beta, and Gamma, this variant is more transmissible than earlier variants; in fact, Delta is thought to be 50 percent more transmissible than Alpha, which itself is more transmissible than the earlier (wild type) variants. This makes it all the more important to get your vaccine jabs.

The Epsilon (ε) variant: This constitutes the B.1.427 and B.1.429 variants, known informally as the California variants. Studies have suggested that Epsilon resists neutralization by antibodies stimulated by the vaccines, but not quite as badly as Delta resists. Thus, the concerns about Epsilon escaping immunity are slightly less compared with concerns about Delta. This is one more reason to get your vaccine jabs.

As you consider the new variant names and what’s happening in terms of how easily the variants spread, also remember from our previous discussions that COVID-19 disease is worse in pregnant women, compared with that in healthy, young, non-pregnant women. As with influenza prior to the COVID-19 pandemic, any cases of young and middle age, otherwise healthy people dying occur only among the unvaccinated. So, once again, Get yourself jabbed..

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.