Alpha, Beta, Gamma, Delta and Omicron viruses are all different variants of SARS-CoV-2, shortened by the World Health Organization ( WHO ) to COVID-19.  The current BA.5 dominant virus is a subvariant of the Omicron subvariant.    Read this summary   by WHO to learn about the evolution of COVID-19. In August of last year, 2021, WHO was especially concerned about the emerging Delta variant, and had already designated variants Eta, Iota, Kappa and Lambda, plus 13 additional variants, or 25 variants in all.  Then came Omicron to completely dominate.   In November of 2021 the state of the field was: While not every one of the thousands of COVID-19 variants gets a Greek letter, the list of them has piled up to omicron, the 15th symbol on the Greek alphabet. Alpha, beta, gamma delta and omicron are all currently labeled as “variants of concern,” the highest alert level from the World Health Organization. There are two other ranking stages underneath that one...