Omicron's Intrinsic Gene-Gene Interactions Jumped Away from Earlier SARS-CoV-2 Variants and Gene Homologs between Humans and Animals

Omicron and its subvariants have become the predominant SARS-CoV-2 variants worldwide. The Omicrons basic reproduction number (R0) has been close to 20 or higher. However, it is not known what caused such an extremely high R0. This work aims to find an explanation for such high R0 Omicron infection. We found that Omicrons intrinsic gene-gene interactions jumped away from earlier SARS-CoV-2 variants which can be fully described by a miniature set of genes reported in our earlier work. We found that the gene PTAFR (Platelet Activating Factor Receptor) is highly correlated with Omicron variants, and so is the gene CCNI (Cyclin I), which is conserved in chimpanzee, Rhesus monkey, dog, cow, mouse, rat, chicken, zebrafish, and frog. The combination of PTAFR and CCNI can lead to a 100% accuracy of differentiating Omicron COVID-19 infection and COVID-19 negative. We hypothesize that Omicron variants were potentially jumped from COVID-19-infected animals back to humans. In addition, there are also several other two-gene interactions that lead to 100% accuracy. Such observations can explain Omicrons fast-spread reproduction capability as either of those two-gene interactions can lead to COVID-19 infection, i.e., multiplication of R0s leads to a much higher R0. At the genomic level, PTAFR, CCNI, and several other genes identified in this work rise to Omicron druggable targets and antiviral drugs besides the existing antiviral drugs.