An analysis by Claudia Langenberg (MRC Epidemiology Unit) and collaborators from UCL, University College London Hospitals NHS Foundation Trust, and Health Data Research UK, indicates that at least 20% of the UK population has a high-risk underlying condition for COVID-19 infection listed by Public Health England.
 
The authors have created a publicly accessible COVID-19 risk calculator showing how age, sex and underlying health conditions can affect mortality rates in different scenarios. In an article, published in The Lancet, they argue that the analysis, which used NHS health records from 3.8 million adults in England, shows that the UK government must ensure that measures to ease the lockdown take into account this clinical vulnerability.