CDC shows new BQ.1 and BQ 1.1 Omicron subvariants account for 44% of US COVID-19 cases

Data from the US Centers for Disease Control and Prevention (CDC) has estimated that the two new Omicron subvariants, BQ.1 and BQ.1.1, accounted for over 44% of US COVID-19 cases for the week ending 12 November, compared with over 32% in the previous week.

BQ.1 made up an estimated 20.1% of circulating US cases for the week ending 12 November, while BQ.1.1 accounted for nearly 24.1%, according to the CDC.

The CDC closely tracks a wide range of Omicron sublineages, with BQ.1 and BQ.1.1 drawing recent attention, as well as BA.5, which has been the dominant subvariant of COVID-19 in the US since early July.

BQ.1 and BQ.1.1 are among the more than 300 sublineages of the Omicron variant circulating globally, 95% of which are direct descendants of BA.5, the World Health Organization reports.

There is currently no evidence linking the new variants with increased severity of the virus compared to the BA.4 and BA.5 subvariants, but they have shown an increasing presence in countries including Europe, Singapore and Canada.

As with other variants of the virus, the risk of becoming seriously ill remains highest for people who are elderly or who have significant underlying health conditions.

The BA.5 subvariant is estimated to make up about 29.7% of cases in the US, compared with nearly 41.1% in the week ended 5 November, according to the CDC.

Those who have had COVID-19 before are still susceptible to infection, but vaccines are helping to protect against serious illness. However, the CDC reports that uptake of the new bivalent booster has been low since the organisation recommended it in September.

More than 26 million people aged over five years have received an updated booster, making up only 8.4% of the US population.

The rising cases of BQ.1 and BQ.1.1 has led regulators and vaccine manufacturers to monitor the new variants more closely in case they start to evade protection offered by current vaccines.

Based on international reports, the CDC said it is also keeping ‘a close eye’ on the XBB variant, a recombinant of BA.2.10.1 and BA.2.75 sublineages, but reports that it is still ‘very rare’ in the US.