The Variants, Explained

Throughout the course of the recent pandemic, I feel as though I have recevied more education in the greek alphabet than ever before! Titles such as gamma, alpha, omicron, and delta were thrown around incessantly, yet I never truly understood what they meant until I studied them more closely. I knew that viruses tended to mutate thanks to the four times I’ve watched the movie Contagion, but I didn’t know how this applied to our current SARS-CoV-2 pandemic. An article by The New York Times was able to shed some light on the topic for me. It explained that viruses are constantly mutating, and a variant is deemed a variant when a collection of viruses all boast the same group of mutations.

In the case of the coronavirus, the mutations of concern occur in regards to the spike proteins (The New York Times). Through our studies in microbiology, I have learned that RNA viruses such as COVID-19 are much more prone to mutations than DNA viruses due to replicating errors. According to the World Health Organization, these errors effect the order of amino acids in a viruses’ RNA, triggering the development of different proteins. Scientists have been able to identify specific amino acid sequences of concern and watch them (World Health Organization). In class, we learned that this is the reason why being an RNA virus is considered a virulence factor, as changes in the proteins a virus produces can lead to it becoming more infectious or deadly.

The above graphic highlights important “clusters” of mutations in the Omicron coronavirus variant. Graphic courtesy of The New York Times.

As explained in The New York Times article, the Omicron variant has a unique combination of 50 mutations, 30 of which pertain to the spike proteins which “the coronavrius uses to attach to human cells” and infect them (The New York Times). In comparison to Omicron’s 50, the Delta variant was home to at least 12 mutattions that also modified the viruse’s spike proteins (The New York Times). These mutations contributed to the viruse’s abiltiy to dock onto a human cell as well (The New York Times). In increasing the virus’ abiltiy to attach to a human cell, the infection rate of the virus is increased, as it can more easily begin to replicate and take up residence in a human, causing illness (The New York Times). It is for this reason that the Delta variant and the Omicron variant became more prominent than the original strain of SARS-CoV-2, because these mutations enabled them to more rapidly spread and had a much lower infectious dose.