Text messages and letters are due to be sent out this week as part of the next phase of the vaccination programme.
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The rollout comes as almost 850,000 people have already booked in for their third dose since the national booking system opened for booster appointments on 21 September.
Who can get a booster jab?
The NHS is currently only offering a booster dose to people aged 50 and over, those in care homes and frontline health and social care workers.
All those who are clinically extremely vulnerable, and anyone aged 16 to 65 in an at-risk group for Covid (who were in priority groups one to nine during the initial vaccine rollout), are also eligible for the jab.
Those eligible can only receive a booster dose if it has been at least six months since the second dose was administered.
Health and Social Care Secretary Sajid Javid said: “Thanks to the extensive preparations of the NHS, the autumn booster programme is being rolled out rapidly to those most at risk and a further one million people are being invited to come forward this week.
“A booster vaccine will prolong the protection they have already developed from first and second doses ahead of the winter.
“I urge everyone eligible to get their Covid-19 and flu vaccines as soon as they can.”
Where can I get my booster dose?
The booster programme is being delivered through existing sites across the country, including pharmacies, hospital hubs, GP practices and vaccination centres.
Which vaccine will I get?
In line with guidance from the Joint Committee on Vaccination and Immunisation (JCVI), those eligible for a booster jab will be given either one dose of the Pfizer vaccine or a half dose of the Moderna vaccine.
How do I book?
People should receive a letter or a text inviting them to book their booster vaccine dose from this week.
This can be done online via the NHS national booking system.
The booking system will only allow you to book your third dose if it has been at least six months since you received your second jab.
You should wait to be contacted by the NHS before booking your booster. You may be asked to book this online or at a local NHS service, such as your GP surgery.
If you have had a positive Covid-19 test, you will need to wait four weeks before booking your booster from the date you had the test.
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