Table 1.

Five WHO-labeled parent lineage variants of concern during 2020–2022 (outbreak.info, 2024).

WHO Label	Pango Lineage	First Outbreak	Number of Cases Worldwide
Alpha	B.1.1.7	United Kingdom	1,141,525
Beta	B.1.351	South Africa	35,651
Gamma	P.1	Brazil	73,495
Delta	B.1.617.2	India	288,894
Omicron	B.1.1.529	South Africa	1895 *

* Note that Omicron has mutated into many subvariants of itself since the original parent lineage [34].