Label- VE statement on Omicron sublineagesBQ.1 and XBB
As part of its ongoing work to track variants, WHO’s Technical Advisory Group on SARS- CoV- 2 Virus Evolution( Label- VE) met on the 24 October 2022 to bandy the rearmost substantiation on the Omicron variant of concern, and how its elaboration is presently unfolding, in light of high situations of population impunity in numerous settings and country differences in the vulnerable geography. In particular, the public health counteraccusations of the rise of some Omicron variants, specifically XBB and its sublineages( indicated as XBB *), as well asBQ.1 and its sublineages( indicated asBQ.1 *), were bandied.
Grounded on presently available substantiation, the Label- VE doesn’t feel that the overall phenotype of XBB * andBQ.1 * diverge sufficiently from each other, or from other Omicron lineages with fresh vulnerable escape mutations, in terms of the necessary public health response, to warrant the designation of new variants of concern and assignment of a new marker.
XBB *
XBB * is a recombinant ofBA.2.10.1 andBA.2.75 sublineages. As of epidemiological week 40( 3 to 9 October), from the sequences submitted to GISAID, XBB * has a global frequence of1.3 and it has been detected in 35 countries. The Label- VE bandied the available data on the growth advantage of this sublineage, and some early substantiation on clinical inflexibility and reinfection threat from Singapore and India, as well as inputs from other countries. There has been a broad increase in frequence of XBB * in indigenous genomic surveillance, but it has not yet been constantly associated with an increase in new infections. While farther studies are demanded, the current data don’t suggest there are substantial differences in complaint inflexibility for XBB * infections. There is, still, early substantiation pointing at a advanced reinfection threat, as compared to other circulating Omicron sublineages. Cases of reinfection were primarily limited to those with original infection in thepre-Omicron period. As of now, there are no data to support escape from recent vulnerable responses convinced by other Omicron lineages.
- BQ.1 * is a sublineage ofBA.5, which carries shaft mutations in some crucial antigenic spots, including K444T and N460K. In addition to these mutations, the sublineageBQ.1.1 carries an fresh shaft mutation in a crucial antigenic point( i.e. R346T). As of epidemiological week 40( 3 to 9 October), from the sequences submitted to GISAID,BQ.1 * has a frequence of 6 and it has been detected in 65 countries. While there are no data on inflexibility or vulnerable escape from studies in humans,BQ.1 * is showing a significant growth advantage over other circulating Omicron sublineages in numerous settings, including Europe and the US, and thus clearances close monitoring. It’s likely that these fresh mutations have conferred an vulnerable escape advantage over other circulating Omicron sublineages, and thus a advanced reinfection threat is a possibility that requirements farther disquisition. At this time there’s no epidemiologic data to suggest an increase in complaint inflexibility. The impact of the observed immunological changes on vaccine escape remains to be established. Grounded on presently available knowledge, protection by vaccines( both the indicator and the lately introduced bivalent vaccines) against infection may be reduced but no major impact on protection against severe complaint is previsioned. Overall summary
The Omicron variant of concern remains the dominant variant circulating encyclopedically, counting for nearly all sequences reported to GISAID( 1). While we’re looking at a vast inheritable diversity of Omicron sublineages, they presently display analogous clinical issues, but with differences in vulnerable escape eventuality. The implicit impact of these variants is explosively told by the indigenous vulnerable geography. While reinfections have come an decreasingly advanced proportion of all infections, this is primarily seen in the background ofnon-Omicron primary infections. With waning vulnerable response from original swells of Omicron infection, and farther elaboration of Omicron variants, it’s likely that reinfections may rise further.
The part of the Label- VE is to warn WHO if a variant with a mainly different phenotype(e.g. a variant that can beget a more severe complaint or lead to large epidemic swells causing increased burden to the healthcare system) is arising and likely to pose a significant trouble. Grounded on presently available substantiation, the Label- VE doesn’t feel that the overall phenotype of XBB * andBQ.1 * diverge sufficiently from each other, or from other Omicron sublineages with fresh vulnerable escape mutations, in terms of the necessary public health response, to warrant the designation of a new variant of concern and assignment of a new marker, but the situation will be reassessed regularly. We note these two sublineages remain part of Omicron, which is a variant of concern with veritably high reinfection and vaccination advance eventuality, and surges in new infections should be handled consequently. While so far there’s no epidemiological substantiation that these sublineages will be of mainly lesser threat compared to other Omicron sublineages, we note that this assessment is grounded on data from sentinel nations and may not be completely generalizable to other settings. Wide- ranging, methodical laboratory- grounded sweats are urgently demanded to make similar determinations fleetly and with global interpretability.
WHO will continue to nearly cover the XBB * andBQ.1 * lineages as part of Omicron and requests countries to continue to be watchful, to cover and report sequences, as well as to conduct independent and relative analyses of the different Omicron sublineages. The Label- VE meets regularly and continues to assess the available data on the transmissibility, clinical inflexibility, and vulnerable escape eventuality of variants, including the implicit impact on diagnostics, rectifiers, and the effectiveness of vaccines in precluding infection and/ or severe complaint.
Source link: https://www.who.int/
