Viral Variants: Race for Survival

Aditi Bhargava
9 min readJul 8, 2021

The dreaded delta, delta+, and lambda variants of SARS-CoV-2. Are these variants really deadlier than the first identified strain of SARS-CoV-2 in patients from Wuhan or the other over 800 variants? Do these variants cause more severe disease or symptoms? What is the mortality rate caused by dreaded delta variants since first identified in February 2021 in India? This information is incorrect, as one of the Delta variants did not originate in India, nor did it first appear in 2021, but has been around since the beginning of the pandemic (Fig. 1); it just wasn’t a predominant variant [1].

Figure 1. One of the Delta variants, G614 , has existed since the beginning of this pandemic. Figure from Journal article “Tracking Changes in SARS-CoV-2 Spike: Evidence that D614G Increases Infectivity of the COVID-19 Virus”, Cell, volume 182. In this report, authors proposed that the variant G614 was more infectious and was present globally.

The precise numbers of deaths due to Delta variants compared with other variants of SARS-CoV-2 is hard to parse out (Fig. 2); it is not reported clearly in many media or research articles, and I suspect, the numbers are not large and thus reporting is often inane, misleading, creates fear, confusion, and chaos, and perhaps is aimed at scaring people into taking the COVID-19 vaccines.

Figure 2. Screenshots of media articles and some headlines about deaths caused by Delta variants

The Numbers Game.

For its survival, the virus’ goal is not to be so lethal that it wipes out its entire host species; that is an important rule of evolution. However, it is in virus’ interest to be able to infect as many hosts as possible and replicate (multiply to produce copies). The Delta variant, by all accounts, seems to do just that (Fig. 1). Delta is not deadlier, just more transmissible; the disease and symptoms are comparable to the first variant identified. What is the evidence so far that supports this statement? Before I review the evidence, let’s be on the same page about what are viral variants in general, and specially, the much-hyped Delta variant.

Briefly, a variant is a change or “mutation” in the virus’ genome. The SARS-CoV-2 is a single and plus-strand RNA virus, hence, the genome itself can serve as messenger RNA (mRNA) to code for proteins once the virus enters a host cell. An mRNA carries all the information (or code) that can be used by cells to make a specific protein by a process dubbed as translation (from the language of RNA to the language of amino acids that make up proteins, hence translation), whereas proteins are…

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Aditi Bhargava

Dr. Aditi Bhargava is a molecular neuroendocrinologist with research focus on sex differences in stress biology and immunology.