In the days BC (Before Covid), most people learned Alpha, Beta and Gamma besides Pi in school. These are the first 3 of the 24 Greek letters. Those who went on to study physical sciences or engineering (or even economics and finance) usually ended up making the acquaintance of more Greek letters (both upper case and lower case, so there are actually 24 * 2 = 48 characters).
How many of these have you met before?
https://en.wikipedia.org/wiki/Greek_alphabet#Letters
Covid variants have now got up to the 15th letter (Omicron) after skipping the 14th (Xi. Guess why?)
Next are Pi and Rho.
But if there are more than 24 variants, what then? Should we start using the small letters? That gives 24 more. Or combine them-e.g. Delta-Omicron is already here. Or start something else-naming the variants after signs of the Zodiac such as Aries, Taurus etc.
We have already passed through Zeta, which would have reminded you of https://en.wikipedia.org/wiki/Catherine_Zeta-Jones
Then there is this limerick:
abn397 