SARS-Cov-2 Variants: Biological and Mathematical Considerations for Nomenclature

Coronavirus (CoV) is one of the most widely used words during the past two years. If it were announced that Delta CoV only affects animals such as pigs and wigeons while Omicron CoV does not even exist, surely people would be offended and question the credibility of whoever stated this. But both statements are true, scientifically. Of note, it was stated Delta CoV and Omicron CoV, not Delta variant or Omicron variant of SARS-CoV-2. Such potentially confusing naming of a globally important virus therefore warrants further analyses. At the subfamily level, CoVs are divided into four genera (Alpha, Beta, Gamma, Delta) and only viruses of the Alpha and Beta branch infect humans. Now that the Omicron variant of SARS-CoV-2 have taken over from the Delta variant globally, the issue of the double use of genus labels (Alpha, Beta, Gamma, Delta) for variant naming is mitigated. However, we can still pause and ponder whether the Greek symbols alone are indeed ideal for labeling waves of SARS-CoV-2 variants. Here we propose additional criteria for naming of variants that considers specific biological and molecular characteristics of the virus-cell interaction. Our aim is to define a biological and structurally defined metric that can be used to distinguish SARS-CoV-2 variants interactions with host cells. This metric could find utility with numerous human viruses and provide an additional parameter for improved naming of viruses.