Pandemics and the English Language: Concepts Critical for Conversing About COVID-19

Abstract

We consider the multiple senses of several key terms that are used to discuss the ongoing COVID-19 pandemic and clarify meanings of the corresponding concepts. Topics addressed include: 1) the meaning of immunity to an infectious agent in varying medical and scientific contexts, 2) the scientific factors that influenced the rapid generation and clinical implementation of safe and effective vaccines for COVID-19, 3) the difference between mutational abrogation of reactivity with B- or T-cell antigen receptors (immune escape) versus active interference with host immune mechanisms mediated by gene products encoded within the genome of the infectious agent (immune evasion), 4) the different ways by which the COVID-19 pandemic has "caused" deaths, and 5) briefly, the challenge of precisely defining the term pathogen.

Keywords: COVID-19; SARS-CoV-2; cause of death; coronavirus; immune escape; immune evasion; immunity; mRNA; pathogen; relational variable; vaccine.

Figure 1.

Scientific factors contributing to the relatively rapid development of safe and effective SARS-CoV-2 vaccines. The schematic diagrams from left to right allude to the roles of prior research on structure-guided vaccine design, previous work focused on the immunologic attributes of coronaviruses similar in key respects to SARS-CoV-2, critical features of SARS-CoV-2 itself, and past efforts to develop the use of nucleic acids that encode immunogens to be produced by recipient cells as well as viral vectors and nanoparticles for vaccine delivery to host cells.

Figure 2.

Schematic illustration of the key differences between the mechanisms of what we suggest corresponds to immune escape (top) versus what corresponds to immune evasion (bottom). Our view is that immune escape should refer to one or more mutations in the genome of a virus or other infectious agent that meaningfully decrease recognition of a key pathogen-associated antigen by antibodies or T-cell receptors. In contrast, immune evasion should correspond to the situation where 1 or more gene products encoded in the genome of the infectious agent function to inhibit or otherwise undermine relevant immunological processes of the host, thereby hindering clearance or destruction of that agent by those host mechanisms. The example of viral proteins that interfere with the production or functioning of type I interferons is used to illustrate the concept of immune evasion.