The Implications of the variants of the virus associated with COVID-19
What is a SARS-CoV-2 (the virus that causes COVID-19) Variant and How Does it Affect Me?
The words “COVID-19 variant” have become a part of the pandemic story. Just what, exactly, is a COVID-19 variant, and why is it important to understand?
A viral variant refers to a virus that has a genetic makeup that is different from the parent strain. For COVID-19 that means the genetic coding materials of the virus, the RNA, has been genetically altered, or mutated, from that of the parent COVID-19 strain.
Each time a biological entity divides or reproduces itself, mistakes can be made; the resulting product, then, not exactly resembling the parent. In the big picture, this phenomenon happens very infrequently. Copying of the genomic material, RNA in the case of a coronavirus, is extremely accurate. Nevertheless, mutations happen. But in a pandemic, or any situation in which a virus or living creature is replicating at a very high rate, these rare mistakes accumulate.
Unfortunately, in the US we have a virus that is present in high numbers and reproducing at a very rapid rate. As a result, variants have a greater chance of appearing and thriving.
Why are variants dangerous?
Variants are dangerous when they have a selective advantage, such as the ability to more easily infect people, or the ability to avoid vaccine-induced immunity. This allows the new virus to spread and outcompete the parental variant. This happened with the UK variant (officially known as B.1.1.7) which became the dominant variant there, and is now spreading in the US.
How are variants detected?
The best way to fully characterize variants right now is to do a genetic analysis (sequence analysis) of the variant, rather than just a PCR or antibody test. This takes time and money, and cannot be done for all viruses or infected people.
Do we know how many variants are present in the US?
The US performs fewer tests in reference to the number of cases that are present compared to other countries. That low rate of testing makes it difficult to identify the number of variants circulating in the US.
What are they talking about when they say a given vaccine is or is not effective against a given variant?
Let’s imagine that a virus was made of 100 lego blocks (i.e. nucleotides). Let’s say that you made the vaccine against blocks 40 to 45 of the 100. Now, let’s say that the new variant virus had 99 blocks that were the same as the parent, but block 42 was different. The vaccine may not be as effective against this variant if it needed to find something in that block 42 to be effective at preventing illness.
What do we do if there are many variants out there?
The most important thing you can do is to continue to follow recommended containment and protection policies. Wear masks. Social distance. Wash your hands. Avoid crowded places. Get a vaccine when it is your time. Sleep. Decrease stress as much as possible. Find something to make you laugh.
Should I still get vaccinated if there are new variants out there?
Yes, you should, for multiple reasons.
The vaccines that are approved are effective against most of the known variants, and they are very effective.
Even if a variant arises against which the vaccines are ineffective, we still need to control the viruses for which the vaccines are effective while updated versions of the vaccines are developed.
It is important to reduce the numbers of viral cases because this reduces the number of variants that will emerge.
Kimberly Gandy, M.D., Ph.D. is a Northwestern/Stanford/Duke trained physician-scientist with over 25 years of experience at the intersection of science, medicine, and technology.
Jos Domen, Ph.D.is a University of Amsterdam and Stanford trained cell biologist and immunologist that has run laboratories at Duke and elsewhere, and published extensively in the scientific literature.