For those interested, here's the 2023 version, which notes (scroll to page 15) 'pandemic' (54) as the most likely
catastrophic risk (less likely are CBRN attack (1-5%), Failure of the National Electricity Transmission System (1-5%), civil (ie UK) or foreign nuclear fallout (<0.2%).
Significant most likely risks include: Outbreak of an emerging infectious disease (55) at 5-25%.
5-25% means "most unlikely in the next 5 years" btw.
https://assets.publishing.service.g...e/1175834/2023_NATIONAL_RISK_REGISTER_NRR.pdf
And early on there's a special box about the last pandemic:
"The most significant risk to materialise in the UK in recent years
has been the COVID-19 pandemic. This has impacted all aspects
of society and will have consequences into the future.
The risk of a pandemic has long been identified as one of the
most serious risks facing the UK. The reasonable worst-case
scenario used for planning purposes has in previous versions
been based on an influenza-like illness pandemic. Any new
pathogen transmitted by the respiratory route is likely to share
characteristics with influenza in that it can spread rapidly
via close proximity, can travel rapidly and there are few easy
immediate countermeasures. It has therefore been a planning
assumption that a plan for pandemic influenza would have
considerable overlap with a plan for other diseases easily
transmitted by the respiratory route.
The lessons from COVID-19 have been incorporated into the
government’s risk assessment methodology. The reasonable
worst-case scenario has been reshaped into a more generic
pandemic scenario reflecting a broader range of possible
manifestations, and additional impacts, measures and data have
been incorporated into the assessment."