The Omicron 5 variant of Sars-CoV-2 and its descendants are losing ground worldwide. Undermining them is the Omicron 2 family which is now growing driven by its flagship sublineage, Centaurus for social media, that is BA.2.75 and similar. There is movement at Omicron, even if BA.5 with its ‘children’ continues to be dominant globally: it represents 68.4% of the viral sequences sent to the Gisaid database in week 48 (from 28 November to 4 December), but the prevalence of these lineages is decreasing. Omicron 5 is held high by Cerberus, BQ.1 and sons, which is at 42.5%. But the latest data available see BA.2 in particular rearing its head together with its descendants, mainly due to Centaurus and offspring: together they are now on the increase and represent 12.6% of the sequences deposited in the week monitored by the World Organization for healthcare.
BA.4 and its lineages are in decline, with a prevalence of 1.2% at week 48. Unassigned sequences (presumably Omicron) accounted for 12.2%, while ‘other lineages’ accounted for 5.9%. This is the picture that emerges from the latest weekly update on Covid, published by the WHO. Globally, the UN Health Agency points out, there are “6 variants currently under monitoring which” have the situation in hand and “represent 72.9% of the prevalence at week 48”. These mutants “replaced previous descendant lineages of BA.5: they are BQ.1 (42.5%), BA.5 with one or more of 5 mutations (13.4%), BA.2.75 (9.8%) , the recombinant XBB ‘Gryphon’ (6.1%), BA.4.6 (1%) and BA.2.30.2 (0.1%).
Based on the currently available evidence, “there is no indication of greater severity associated with these monitored variants compared to previous Omicron lineages”, reiterates WHO which in the previous update had also taken stock of the evolution of descendant variants of Omicron, highlighting that this super crowded ‘version’ of Sars-CoV-2 “continues to show genetic diversification and has led” by now “to more than 540 descendant lineages and more than 61 recombinants. However, only some of these continue to increase predominantly, while others remain only a few surveys”.