World Faces New Threats From Fast-Mutating Omicron Variants

The subvariants known as BQ.1.1, BQ.1, BQ.1.3, BA.2.3.20 and XBB are among the fastest-spreading of the main omicron lineages. Based on UK data, the BQ variants, as well as BA.2.75.2 and BF.7 are the most concerning due to their growth advantage and immune evasiveness, the country’s health security agency said on Oct. 7. BF.7 has also been gaining ground in the US, where it accounted for 4.6% of Covid cases in the week ending Oct. 8, from 3.3% the week before, according to the Centers for Disease Control and Prevention. The Atlanta-based agency noted BA4.6 was the most prevalent after BA.5, accounting for 13.6% of cases in the first week of October, from 12.7% the week before. In Bangladesh and Singapore, the XBB strain has been linked to a small surge in cases.