People aged 30 and over will be able to book a Covid-19 booster jab from Monday in England.
The national booking system will open to everyone aged 30 to 39 so that they can arrange to get the top-up jab three months on from their second dose.
The extension of the NHS vaccine programme comes as scientists advising the Government warned that tougher Covid restrictions may be needed to prevent the Omicron variant causing anywhere between 25,000 to 75,000 deaths in England over the next five months.
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 possibleSajid Javid
NHS England said the rollout has been accelerated in the face of Omicron, with data from UKHSA suggesting that booster doses give good protection against the new variant.
People can make their booking two months on from their second dose – a month in advance of becoming eligible to receive the jab.
There are around 7.5 million people aged 30 to 39, and 3.5 million of those are eligible from Monday.
Dr Emily Lawson, head of the NHS Covid-19 vaccination programme, said: “Following the updated guidance from the JCVI, which shortened the interval between second and booster doses, NHS staff are redoubling their efforts to protect the public from the virus.
“The NHS vaccination programme, the biggest and most successful in health service history, will from tomorrow offer top-up jabs to everyone aged 30 and over three months from their second jab.
“With the emergence of the new variant and the rising case numbers, there has never been a more important time to get boosted. So, when it’s your turn, come forward and book in.
“The vaccine programme has been designed and delivered by NHS staff but it could not have been rolled out so quickly without the support of our fabulous volunteers.
“So, if you are interested in helping us, we have roles available – from marshalling car parks as a volunteer or taking on a paid role in admin or as a vaccinator, please do look at the opportunities available. You would be helping us to save lives.”
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.”
Experts from the London School of Hygiene & Tropical Medicine (LSHTM), who also sit on the Scientific Pandemic Influenza Group on Modelling (SPI-M) or the Scientific Advisory Group for Emergencies (Sage), used experimental data to look at how Omicron may transmit as the country heads into 2022, and predicted a large wave of infections in January.
On Friday, 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.
But the UKHSA said a booster dose gives around 70% to 75% protection against symptomatic infection with Omicron, as it urged people to have their boosters.