- Nov 11, 2022
- 2 min read

The ABCs of XBB, BQ.1 and BQ.1.1 Omicron Subvariants

BA.1; BA.1.1; BA.2; BA.2.12.1; BA.3;BA.4; BA.5….

The Omicron subvariants seem like an alphabet soup of letters and numbers; you are forgiven if you have given up keeping track.

However, there are a few strains that you should take note of if you live in Singapore: XBB, BQ.1 and BQ.1.1.

These are the new Omicron subvariants to hit our shores and are closely monitored due to their greater ability to evade immunity, allowing them to spread quickly.

Here’s a quick read to keep you up to date.

What to know about….

XBB

XBB is currently the predominant subvariant causing Covid-19 infections in Singapore.

XBB is better able to evade the immunity caused by vaccines and previous infections and its ability even outperforms its ancestor, BA.5, which was how it replaced the latter to be the dominant subvariant driving Covid-19 infections in the country.

On the bright side, a recent update from WHO states that there is currently no evidence that XBB causes more severe disease (i.e. how bad your symptoms or illness is upon infection) than the other Omicron family variants. There are also indications that the ongoing wave of Covid-19 infections driven by XBB has peaked and is shifting to a downward trend.

BQ.1 and BQ.1.1

BQ.1 and BQ.1.1 are also subvariants of the Omicron variant BA.5, with BQ.1.1 having just one mutation more than BQ.1.

Their additional mutations allow the viruses to dodge protective antibodies from prior infection or vaccination, similar to XBB. As a result, they are quickly gaining traction in the US, collectively accounting for 27% of infections as of October 29 and have also been identified in several countries in Europe. 4 imported cases of BQ.1 and BQ.1.1 have been confirmed in Singapore as well. WHO has therefore suggested that these two strains warrant close monitoring due to their transmissibility and potential to cause another spike in infections.

Currently, there is no data that suggests BQ.1/BQ.1.1 have increased disease severity upon infection.

Are current vaccines still effective?

Current vaccines are effective in preventing severe illness from these 2 strains, and it has been observed that people who are more recently boosted are less likely to be infected by newer variants.

If you want something more effective, you may consider receiving a booster shot with the newest bivalent vaccines which offer protection against both the original and Omicron variants.

Symptoms to be mindful of

XBB and BQ.1/BQ.1.1 infections have common COVID-19 symptoms associated with many of the Omicron subvariants: