Over the past year, we have learned a lot about the COVID-19 virus. Much of what we have learned has been how to protect ourselves, how to protect those we care about, how to treat the virus, and most recently how to prevent it with the vaccine. Each lesson has helped us feel more in control and a bit safer.
With the introduction of variants due to COVID-19 mutations, we again find ourselves questioning how safe we are, and the mental weariness of the unknown begins to set in again. The best way to combat this unease is to learn about these variances, how they happen, and how they can affect our efforts to combat the virus.
It is first important to understand that organisms in general, be it humans, plants, insects, bacteria or viruses, undergo genetic mutations which can be beneficial or detrimental. Although viruses are not technically alive, they do mutate and evolve, and different types of viruses mutate at different rates. For example, the SARS-CoV-2 coronavirus mutates approximately every 11-15 days. This is about half the rate of influenza and about a quarter of the HIV rates. Natural selection then amplifies traits that are beneficial to the viral particle.
We know the coronavirus has 12,700 identified mutations, 12 main types of the virus, five strains and several variants. Most of the variants of concern contain mutations in the receptor-binding domain (RBD). It seems these mutations are responsible for increased viral infectivity, virulence and immune evasion potency.
The virus binds to a human target cell receptor, injects its genetic material and takes over the cell, turning into a virus replicating factory. As it replicates, mutations can take place and either help or compromise the virus. Many of the identified mutations are inconsequential as these do not change the biology of the virus.
Mutations are passed down through lineage, best described as a branch in the family tree. A group of coronaviruses that has the same inherited set of very distinctive mutations is called a variant.
The lineage becomes known as a strain, and in this specific example, COVID-19 is caused by a coronavirus strain known as SARS-CoV-2.
Through the course of the pandemic, we have identified several variants globally, five of which are of concern as the strains are associated with higher transmission rates that may impact the effectiveness of vaccine and therapy, and it seems increased mortality may be associated with at least one variant.
The first step in understanding the variants and the impact these have in infection, reinfection and possible effects on vaccines and treatments is knowing the mutations. Although there are thousands of mutations so far, seven of those are the most critical to know. In a full version of this article found at srhd.org, I summarized the importance of each mutation and how they have contributed to the “variants of concern” or “variants of interest” we hear about in the news and now know have spread into Washington. These variants include:
•B.1.1.7 – originally discovered in the United Kingdom
•B.1.351 – originally discovered in South Africa
•P.1 and P.2 – originating in Brazil
•B.1.427 and B.1.429 or CAL. 20C – originally identified in California
•B.1.526 and B.1.525– originally identified in New York
•Novel Midwest Variants – identified specifically in Columbus, Ohio
It is important to remember that what most of these variants have in common is a more effective transmission pattern, which has been associated with a surge in infections in various areas of the world. In addition, some data suggest that increased morbidity and perhaps mortality can be associated with some of the variants. The impact on treatment and vaccines is still being determined, although preliminary data points to minimal impact on vaccine efficacy. Moreover, vaccine manufacturers have significant capabilities in the reformulation of vaccines.
We also know the transmission mode is the same as with the wild-type (unchanged) coronavirus, thus preventing infection should follow similar public health guidance: facial coverings, social distancing, avoiding gatherings, and practicing appropriate hygiene and sanitation. These simple rules along with increased immunization and appropriate levels of testing continue to be the key pillars in our management of the pandemic.
As mentioned earlier, my entire article with a full explanation of the mutations and variants of COVID-19 is available at srhd.org. I encourage you to visit the site and learn more. Understanding the virus and knowing what we’re up against helps in understanding mitigation efforts and knowing the part you can play in controlling the spread of COVID-19.
Francisco R. Velázquez, M.D., S.M., is the interim health officer for Spokane Regional Health District.
Local journalism is essential.
Give directly to The Spokesman-Review's Northwest Passages community forums series -- which helps to offset the costs of several reporter and editor positions at the newspaper -- by using the easy options below. Gifts processed in this system are not tax deductible, but are predominately used to help meet the local financial requirements needed to receive national matching-grant funds.
Subscribe to the Coronavirus newsletter
Get the day’s latest Coronavirus news delivered to your inbox by subscribing to our newsletter.