Covid booster jabs will be available to millions more people in England from tomorrow (12 December).
Everyone aged 30 to 39 will be able to book an appointment to get their third vaccine - as long as it is three months on from their second dose.
The move comes amid concerns the UK is facing a major wave of infections in January from the Omicron variant.
Health and Social Care Secretary Sajid Javid said: “The Covid-19 booster programme is accelerating rapidly and more than 22 million people in the UK have already received their top-up, securing vital protection ahead of Christmas.
“This is our national mission – the most recent data shows boosters are the essential defence against Omicron and we are doing everything in our power to get jabs into arms as quickly as possible.
“We are now expanding the offer to over-30s, so please come forward as quickly as possible to get boosted and help our country get ahead in this race with the variant.”
Who is eligible for their third jab from Monday?
There are around 7.5 million people aged 30 to 39 in England.
Approximately 3.5 million of those are eligible for boosters from Monday, NHS England said.
All eligible adults can book their booster jab two months (61 days) after their second dose.
However, the third jab has to take place three months (91 days) on from their second dose.
Does the booster jab protect against the Omicron variant?
Analysis by the UK Health Security Agency (UKHSA) found that the AstraZeneca and Pfizer vaccines provided “much lower” levels of protection against symptomatic infection with Omicron compared with Delta.
However, the agency said that a booster dose gives around 70% to 75% protection against symptomatic infection with Omicron, as it urged people to have their boosters.
Figures released on Saturday (11 December) showed there had been an additional 633 confirmed cases of the Omicron variant reported across the UK.
A breakdown of the data showed there had been a further 618 confirmed cases in England, 11 in Scotland, two in Wales and two in Northern Ireland.
That takes the overall UK figure, as of Saturday, to 1,898 confirmed cases - which was up 50% on Friday’s figure when the total was 1,265.
A version of this article originally appeared on NationalWorld.com