The number of people getting their first jab of the Covid-19 vaccine rose by around 46% in the week up to December 21, the Government said.

In total, 221,564 first doses were administered in England in the week of December 15-21, a 46% increase from the previous week, and 279,112 second doses were administered, a 39% jump, the Department for Health and Social Care said.

The largest increase was seen among young people, with an 85% increase in first doses for those aged 18 and 24 and a 71% increase in first doses for those aged 25 to 30.

In the week up to December 21, more over 60s had had a first dose than during any seven-day period since early June.

Data from the UK Health Security Agency has revealed that two doses of the Covid-19 vaccine, while providing strong protecting from the Delta variant, show substantially reduced effectiveness against symptomatic infection from the Omicron variant over time.

But a third dose provides between 60% and 70% protection against symptomatic infection from Omicron two to four weeks after the booster dose.

The Government and NHS England have expanded the booster programme and launched an advertising campaign urging the public to ‘Get Boosted Now’.

More than 30 million people have already had their third dose and all of those eligible will be offered a booster by the end of the year.

Health and Social Care Secretary Sajid Javid said that it had “never been more vital to get your jabs” and described the recent surge in first and second doses as “excellent”.

“Those initial jabs lay the foundation for the booster jab to protect against Omicron, two doses is not enough and you need to build protection jab by jab and once eligible Get Boosted Now,” he said.

A first and second jab is needed to be eligible for the booster and be protected from Omicron.

“Millions of people have rolled up their sleeves, so let’s build on that momentum and ensure we have the protection we need this winter,” Mr Javid added.

The news comes as a senior NHS doctor warned “stragglers” who were eligible for a booster but had yet not had one that there was “no time to lose”.

“The evidence is clear.

“One or two jabs can help but they do not provide the protection we all need against Omicron,” said NHS national medical director Professor Stephen Powis.

“So if you are eligible for a Covid vaccination but haven’t had one there is no time to lose, you need to get boosted now,” Prof Powis added.

He said that staff and volunteers on the NHS Covid vaccination programme would be working throughout the festive period to “make sure people can get the protection they need as conveniently as possible” and that people could go online to choose from thousands of vaccination sites to book an appointment, “with no need for long queues”.

“It’s the best way to protect yourself, your family and your friends so my message to the stragglers is clear: Don’t delay any longer come forward and sort your jab now,” he said.

Over the festive period, 750 armed forces personnel have been drafted in to support the rollout of the booster programme, while extra vaccine centres and pop-up sites have opened to make it as easy as possible for people to be vaccinated.

Vaccines Minister Maggie Throup said that following the emergence of the Omicron variant, the booster programme had been “turbocharged”, with increased numbers of vaccine sites “making it easier than ever for people to get their jab, whether that’s the first, second or booster”.

“It is heart-warming to see the numbers of people rolling up their sleeves to get their initial doses of a lifesaving Covid-19 vaccine,” she said.

But she added that “two doses” were not enough for protection against Omicron and urged the public to “take advantage” of the accelerated programme and book their booster “to top up your protection for the New Year”.

More than a million slots for vaccinations are still available in the run-up to the New Year.

Although millions of people have received a booster dose in the last few weeks, around 10% of appointments have been missed nationwide while hundreds of thousands of appointments remain unfilled since Prime Minister Boris Johnson urged those eligible to book a third jab.

Hundreds of thousands of people have also been forced to delay their jab after testing positive for Covid-19, as you must wait 28 days between testing positive and receiving a vaccine.

More than seven in 10 people aged 18 and over have now received their booster, with 27,127,951 people who are three months on from their second dose already boosted in England, as of December 24.