The Government has released a full list of those considered most at risk from coronavirus.
So far 55 people in the UK have died from Covid-19 and that number is expected to increase.
On Monday, new public health safety measures were put it place to help reduce the spread of the virus.
Previously, advice from the Government largely said those who were older, vulnerable and had underlying health conditions were most at risk.
Now, the warning has been extended to pregnant women for the first time.
A full list of those classed as more at risk has been issued. They include:
- aged 70 or older (regardless of medical conditions)
- under 70 with an underlying health condition listed below (ie anyone instructed to get a flu jab as an adult each year on medical grounds):
- chronic (long-term) 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, a learning disability or cerebral palsy
- diabetes
- problems with your spleen – for example, sickle cell disease or if you have had your spleen removed
- a weakened immune system as the result of conditions such as HIV and AIDS or medicines such as steroid tablets or chemotherapy
- being seriously overweight (a BMI of 40 or above)
- those who are pregnant
The advice went on to say there were some people who were at an even greater risk of "severe illness" from Covid-19.
People in this category are:
- People who have received an organ transplant and remain on ongoing immunosuppression medication
- People with cancer who are undergoing active chemotherapy or radiotherapy
- People with cancers of the blood or bone marrow such as leukaemia who are at any stage of treatment
- People with severe chest conditions such as cystic fibrosis or severe asthma (requiring hospital admissions or courses of steroid tablets)
- People with severe diseases of body systems, such as severe kidney disease (dialysis)
The Government said anyone who may be at risk should socially distance themselves - and how they can manage while in isolation.
Boris Johnson announced that those in vulnerable groups - including all those over 70 - would be asked to avoid contact by isolating except in very specific circumstances.
The Prime Minister added: "This advice about avoiding all social contact is particularly important for people over 70, for pregnant women and for those with some health conditions."
It could mean avoiding social contact for 12 weeks, with entire households now being asked to self-isolate for 14 days if just one member has symptoms.
Public Health England chief medical officer Chris Whitty described the new guidance for those more at risk as "absolutely critical".
Prof Whitty said: "The group of people who we would want to take this advice particularly seriously are older people above 70, people who in adult life would normally be advised to have the flu vaccination.
"So these are people with chronic diseases such as chronic heart disease or chronic kidney disease, and also - as a precautionary measure because we are early in our understanding and we want to be sure - women who are pregnant."
Anyone with a high temperature or a new and continuous cough or anyone in their household with those symptoms should stay at home, the Government has said.
