Question to the Department of Health and Social Care:

To ask His Majesty's Government what recent assessment they have made of the risk to the public from Omicron subvariants driving a wave of COVID-19 this winter.

The UK Health Security Agency (UKHSA) regularly undertakes risk assessments of emerging COVID-19 strains with academic partners, combining evidence from laboratory experiments, domestic sequencing in the United Kingdom and international datasets. These assessments carry high uncertainty inherent to these sources of data. The most recent assessment, The SARS-CoV-2 variants of concern and variants under investigation in England: Technical briefing 47 was published on 28 October 2022 and copy is attached.

There are currently several sub-lineages of Omicron in circulation globally, each carrying a common set of mutations. Laboratory evidence suggests that these mutations make these sub-lineages more resilient to neutralisation by antibodies elicited from vaccination and past infection. The assessment suggests with moderate confidence that these strains could contribute to increases in cases and hospitalisations in the UK.

The Omicron BQ.1 strain, while currently low in prevalence, accounts for an increasing share of UK COVID-19 cases. The XBB is present in low numbers in the UK, although it has the potential to increase. In Singapore, XBB is now the dominant variant and increased hospitalisations, though transmission attenuated quickly.

During winter, there is typically increased circulation of respiratory viruses, which may contribute to the growth of Omicron sub-lineages and increase the resurgence risk of COVID-19. Autumn booster doses of COVID-19 vaccines have therefore been offered to those aged 50 years old or over or at risk of severe outcomes.