www.gov.uk/guidance/new-national-restrictions-from-5-november
Clinically vulnerable people are those who are:
"aged 60 or over (regardless of medical conditions)
under 60 with an underlying health condition listed below (that is, anyone instructed to get a flu jab each year on medical grounds):
chronic (long-term) mild to moderate respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), emphysema or bronchitis
chronic heart disease, such as heart failure
chronic kidney disease
chronic liver disease, such as hepatitis
chronic neurological conditions, such as Parkinson’s disease, motor neurone disease, multiple sclerosis (MS) or cerebral palsy
diabetes
a weakened immune system as the result of certain conditions or medicines they are taking (such as steroid tablets)
being seriously overweight (a body mass index (BMI) of 40 or above)
pregnant"