I have received the below written answer from the Department of Health and Social Care:
The Department of Health and Social Care has provided the following answer to your written parliamentary question (91818):
To ask the Secretary of State for Health and Social Care, if he will publish the evidential basis supporting the decision to move to covid-19 Plan B. (91818)
Tabled on: 13 December 2021
Prior to the move to Plan B on 8 December 2021, the available data at that time suggested that the confirmed prevalence and transmission of cases of the Omicron variant was high. The Government evaluated a range of emerging evidence and metrics including those discussed in the Scientific Advisory Group on Emergencies’ meetings 97 to 101 and associated meetings, such as meetings of the New and Emerging Respiratory Virus Threats Advisory Group, the Scientific Pandemic Influenza Group on Modelling, Operational sub-group, the COVID-19 Clinical Information Network and the Environmental Modelling Group. These meetings were minuted and published on GOV.UK. Data from the COVID-19 dashboard was also assessed, including the Office for National Statistics’ population survey, the UK Health Security Agency’s vaccine coverage and effectiveness data, National Health Service data, rates of positive tests and international data.
The answer was submitted on 28 Apr 2022 at 12:00.