THE booster doses have been rolled out in England and with the first shot been given to an NHS staff.
The booster jab will be given to the over 50s, health and care workers and younger adults with certain health conditions.
Those eligible should receive a booster at least six months after their second dose, and people will be contacted when it is their turn.
NHS said all those eligible, inclusing people with blood cancer or organ donor recipients, would be contacted.
Hospital centres in England and Wales can now start vaccinating eligible frontline healthcare workers. Some care homes started the rollout on Thursday (16) in England, this weekend in Wales and in Scotland on Monday (20). Northern Ireland begins its booster programme later this month.
The Joint Committee on Vaccination and Immunisation (JCVI) said a booster programme, to run alongside a flu vaccine rollout, was a precautionary approach to ensure vulnerable groups maintained high levels of protection.
Around 4.5 million people in priority groups will be eligible for a booster over the coming weeks, NHS England says, with a further 25 million to be contacted in due course. Pharmacies, GP practices and local vaccination centres will start offering boosters in the coming days.
People will get a call or text from their local GP-led site to get the jab, or will be invited by the National Booking Service, which will start issuing invitations from early next week.
Who is eligible for a Covid booster jab?
- those living in residential care homes for older adults
- all adults aged 50 years or over
- frontline health and social care workers
- all those aged 16 to 49 years with underlying health conditions that put them at higher risk of severe Covid-19, and adult carers
- adults who live in the same house as people who are immunosuppressed
- Care home residents, who are one of the groups most vulnerable to the virus, will be offered a vaccine before the start of November in England.
A protestor is detained by the police during a demonstration against the proposed site of the new Chinese Embassy, outside Royal Mint Court, in London. REUTERS/Carlos Jasso. 
