NHS England data shows 48,355 people across the area were set to receive letters urging them to avoid leaving their home except for in certain circumstances, such as to exercise or attend health appointments, as of February 22.
In Wolverhampton it took the total number of people advised to shield to 20,160 – a 124 per cent increase – and in Dudley it increased to 20,090 – a rise of 60 per cent.
In Sandwell it increased by 106 per cent with the total number of people advised to shield in the area increasing to 26,540 – while in Walsall it increased by 90 per cent to 20,290.
And the data showed in Stafford it increased by 35 per cent with the total number of people advised to shield in the area increasing to 9,025; in Cannock Chase there was an increase of 48 per cent to 5870; and in South Staffordshire it increased by 54 per cent to 6,090 people being advised to shield.
Dudley Council had sent out letters to those residents who had been advised to shield last month, with information on support available.
Councillor Nicolas Barlow, cabinet member for health and adult social care, said: “It is incredibly difficult to ask residents to shield and we recognise the strain this has on individuals and their families.
“But is vital those who are at additional risk of becoming seriously ill if they get coronavirus take all the necessary steps to stay at home.
“Following on from the NHS letter, the council is contacting affected residents in this new group to detail the local support available from ourselves and our partners.”
The initial shielding list included people with single risk factors such as those with various cancers, people on immunosuppression drugs or those with severe respiratory conditions.
It has been expanded after scientists developed a new tool which assesses whether someone is at risk of severe disease or death.
The tool looks at multiple factors including age, ethnicity, body mass index (BMI), other health conditions and also postcode, which is indicative of levels of deprivation.