What is BQ.1? Covid Omicron strain explained, how fast is it spreading, is it a variant of concern in the UK

The BQ.1 Covid Omicron variant and its sub-lineages have the potential to cause a further increase in coronavirus transmission, the UK Health Security Agency (UKHSA) has said.

But what is BQ.1 and how many cases of the variant has the UK had so far? Here’s what you need to know.

What is BQ.1?

BQ.1 is a sub-lineage of the Omicron BA.5 Covid variant, which is the predominant circulating variant in the UK. BQ.1 has been designated as a variant on the basis of it spreading quickly.

There are 2,490 non-UK BQ.1 sequences on GISAID - a global science initiative which tracks Covid variants - and 3,207 UK sequences.

Sequencing analyses the virus sample taken from a diagnosed patient and compares it with other cases.

From 4 July 2022 to 24 October 2022 there have been a total of 3,207 BQ.1 samples uploaded to GISAID from 48 distinct countries, across six continents.

Is BQ.1 a variant of concern?

BQ.1 has been designated as a variant by the UK Health Security Agency - UKHSA - but it is not currently a variant of concern. However, there is the potential for BQ.1 - and its and sub-lineages - to cause a further increase in transmission, the UKHSA said.

This is based on the growth advantage of BQ.1 and its sub-lineages in the UK, based on more than one model, and predictive and laboratory data .

A further 3,004 BQ.1.1 samples - a sub-lineage of BQ.1 - have been uploaded to GISAID since 21 June 2022, spanning 35 countries and six continents.

BQ.1 has a prevalence of 6% and it has been detected in 65 countries. The World Health Organisation said that while there’s no data on severity or immune escape from studies in humans, BQ.1 is showing “a significant growth advantage over other circulating Omicron sub-lineages in many settings”, including Europe and the US, and therefore “warrants close monitoring”.

The WHO said it is likely that these additional mutations have had an immune escape advantage over other circulating Omicron sub-lineages and therefore a higher reinfection risk is “a possibility that needs further investigation”.

However, at this time there is no data to suggest an increase in disease severity. The impact of immunological changes on vaccine escape also remains to be established.

Protection by vaccines - both the original and the newer bivalent jabs - against infection may be reduced, but no major impact on protection against severe disease is currently expected.

TAG-VE - the Technical Advisory Group on Covid Virus Evolution - does not feel that BQ.1 currently needs to be assigned as a new variant of concern, but it remains part of Omicron, which continues to be a variant of concern. This decision will be reassessed regularly and if there is any significant development that warrants a change in public health strategy, WHO will alert its member states and the public.