Question to the Cabinet Office:

To ask Her Majesty's Government, further to the Written Answer by Lord True on 26 January (HL12011), what reasonable worst-case planning scenario estimates were applied to the forecast modelling used to inform the decision to place England under national restrictions to address the COVID-19 pandemic on 5 January, including (1) the modelled projections, and (2) the amended assumptions, based on the increased transmissibility of the B.1.1.7 variant of SARS-CoV-2.

Throughout the pandemic, the Government has used a broad range of health, social and economic evidence to inform decision making. The Scientific Advisory Group for Emergency (SAGE) is responsible for providing coordinated scientific advice to support decisions made by the Government. The SAGE subgroup, the Scientific Pandemic Influenza Group on Modelling (SPI-M), uses estimates across a range of metrics to support this advice, including short term modelling including on cases & hospitalisations. These models include a range of projections based on the observed rates of infection and hospitalisations. The assumptions underpinning these models develop as our understanding of the virus changes.

At the end of October, it was clear that rising infections had the potential to exceed NHS regular and surge capacity within weeks. Case projections showed increases in every region, and that national intervention was therefore necessary.

In December, the SAGE subgroup on New and Emerging Respiratory Virus Threats (NERVTAG), estimated that the B.1.1.7 variant may be up to 70% more transmissible. This informed the rapid escalation of areas and regions through the tier system in late December and a creation of Tier 4. Further analysis across a number of infection metrics, along with SPI-M modelled projections, helped inform the decision that national restrictions were again required on 5 January.