Experts have said that the extra dose will help the most vulnerable stay protected against severe Covid-19 symptoms.
The Joint Committee on Vaccination and Immunisation said that vaccinating these groups was only a "precautionary" measure and did not mean there was any increase in danger to their wellbeing.
Until today (21 March) only people with weakened immune systems had been eligible for a second booster dose.
Below is everything you need to know about the fourth dose, or second booster, and who is eligible.
Who is eligible for a fourth dose of the vaccine?
Those now being offered a second booster from today are:
adults aged 75 years and over
residents in a care home for older adults
individuals aged 12 years and over who are immunosuppressed
What type of vaccine is the fourth booster dose?
The vaccine must be administered at least six months after the first booster dose.
Where can I get the fourth dose in Leeds?
If you're eligible, a GP or your hospital specialist should contact you to let you know you can get a 4th dose.
You may also get a letter from the NHS advising that you may be eligible and to discuss this with your doctor.
You'll usually get vaccinated at your local hospital or a local NHS service such as a GP surgery.
A full list of sites in Leeds offering vaccinations is available on the NHS website.
Can I book my fourth dose online?
If you're aged 12 or over, you can also book your 3rd dose or booster (4th dose) appointment online.You'll need to bring with you either:
* a letter from your GP or hospital specialist inviting you for a 3rd dose or booster (4th dose)
* a hospital letter that describes the condition or treatment that caused you to have a severely weakened immune system at the time of your 1st or 2nd dose
* a prescription or a medicine box with your name and the date showing when the medicine was prescribed – this must show that you had a severely weakened immune system at the time of your 1st or 2nd dose
If you think you’re eligible for a 3rd dose or booster (4th dose) but you do not have a suitable letter, prescription or medicine box, you may still be able to get your vaccination.