In November 2021, a new SARS-CoV-2 variant, Omicron, was described for the first time and has become the globally dominant variant. Recent sequencing has revealed two new sub-variants of Omicron BA.4 and BA.5 that drive the current wave and contain further mutations in the receptor binding spike domain compared to earlier sub-variants. Importantly, the Oxford researchers showed that the neutralization of BA.4 / 5 in people even triple vaccinated with mRNA (Pfizer) or vector vaccine (AstraZeneca) was reduced by more than 2-fold compared to the initial BA.1 sub-variant. which suggests that vaccine immunity is declining. Work published in Cell.