More than four million people across the UK have had a Covid booster.
Healthy children aged 12-15 are being offered a single dose.
Who will get a booster?
Across the UK, booster jabs are being offered to:
- Frontline health and social care workers
- Older adults in residential care homes
- People aged 16-49 years old with underlying health conditions which put them at greater risk of severe Covid
- Adults sharing a home with vulnerable people
The dose must be given at least six months after a second vaccination. Usually it will be Pfizer or Moderna.
In addition, some people with severely supressed immune systems need a third jab to be considered fully vaccinated. They may also get boosters at a later date.
Which children can have the Covid vaccine?
All 12 to 15-year-olds are being offered a single Pfizer Covid jab.
The rollout has already begun in England, Scotland and Wales, and will start shortly in Northern Ireland.
Most doses are being given in school, but children in England will soon be able to visit vaccination centres.
There is no vaccine currently approved for under-12s in the UK.
Why are infections high despite vaccinations?
Almost 80% of all over-12s are fully vaccinated, but Covid cases are rising.
Vaccines are designed to protect people against becoming seriously ill or dying from Covid.
According to Public Health England (PHE):
- Vaccines are 96% effective at preventing hospitalisation
- Covid deaths in the double-jabbed are four times lower than in the unvaccinated
But they're less effective at stopping people catching Covid or passing it on.
Effectiveness also depends on how well each vaccine works against individual variants.
PHE studies suggest two vaccine doses protect 80% of people against getting symptoms from the Delta variant.
How can I book my vaccine?
In England, adults and those within three months of turning 18 can book first or second jabs online, by calling 119, or visiting a walk-in clinic. Sixteen and 17-year-olds should contact their GP.
Parents of twelve to 15-year-olds will soon get a letter about appointments at vaccination centres. Children will also have to consent on the day.
Frontline health or social care workers can book their booster jab online, but other groups should wait to be contacted by the NHS. If more than six months has passed since their second dose they can call 119.
In Scotland, over-16s can register for their first or second vaccine online, or by calling 0800 030 8013. Over-12s can go to drop-in vaccination clinics. Invitations will be sent to those entitled to a booster.
Which vaccine will I get?
People who are under 40 or pregnant are being offered Pfizer or Moderna rather than Oxford-AstraZeneca, because of a possible connection with extremely rare cases of blood clots.
Under-18s are currently being offered Pfizer, although the Moderna vaccine has also been authorised for use in children.
Is vaccination compulsory?
Not for most people.
But the government says it's "highly likely" both Covid and flu jabs will be compulsory for frontline NHS and care workers in England.
Being fully vaccinated is also a condition of entry for nightclubs and some other events in Scotland and Wales.
It also means you don't have to self-isolate after holidaying abroad or if a contact tests positive (as long as you test negative).
What about side effects?
The most common ones include a sore arm, headache, chills, fatigue and nausea.
They are part of the body's normal immune response to vaccines and tend to resolve within a day or two.
There are extremely rare but occasionally fatal cases of people developing blood clots after taking the AstraZeneca vaccine.
Separately, a very small number of people have experienced a severe allergic reaction after receiving the Pfizer vaccine.
You should discuss any existing serious allergies with your healthcare professional before being vaccinated.