Booster jabs are now being offered to all adults over the age of 18 as the UK faces an 'Omicron emergency'.
The prime minister said the country faces a 'tidal wave' of infections as he announced an acceleration of the NHS Covid-19 vaccination programme.
From today, all eligible adults aged 18 or over can get a booster jab at a walk-in centre.
READ MORE:
From Wednesday, the national booking service will open to people aged 18 and over who want to book an appointment in advance.
Booster vaccines are administered at least three months after a person has had their second dose of the vaccine.
But what if you have tested positive for Covid-19?
If you have recently recovered from the disease, you may have to wait slightly longer before getting your booster.
Anyone who is self-isolating while they have the virus must stay at home. You can not leave isolation to get your jab.
Once your isolation period is over, you then have to wait at least four weeks before you can have your booster jab.
The prime minister has brought forward the target of offering a Covid-19 booster jab to every adult from the end of January to the end of December.
He said everyone eligible aged 18 and over in England will have the chance to get their booster before the new year.
Mr Johnson said expanding the vaccine programme will require an “extraordinary effort”.
He said opening hours will be extended so that clinics are open seven days a week, with more appointments early in the morning, in the evening, and at weekends.
He also said thousands more volunteer vaccinators will be trained.
Analysis by the UK Health Security Agency (UKHSA) has found that the AstraZeneca and Pfizer vaccines provide “much lower” levels of protection against symptomatic infection with Omicron compared with Delta.
But, the UKHSA said a booster dose gives around 70 per cent to 75 per cent protection against symptomatic infection with Omicron.
