sub-variants of Omicron-BA.5 and BA.5 are more transmissible, and can dodge some of the immune protection conferred by previous infection and vaccination.
According to Nature's magazine, the rise BA.4 and BA.5 — as well as that of another Omicron offshoot in the US — could mean that SARS-CoV-2 waves are beginning to settle into predictable patterns, with new waves periodically emerging from circulating strains. “These are the first signs that the virus is evolving differently" compared with the first two years of the pandemic when variants seemed to appear out of nowhere, Tulio de Oliveira, a bioinformatician at Stellenbosch University in South Africa told the magazine.
Omicron's BA.4 and BA.5 subvariants emerged in mid-December 2021 and early January 2022 in South Africa first, thereafter, they gradually spread to other countries.