The NHS Confederation says it has heard reports some vaccine clinics are only a third full as cases of the Omicron variant continue to rise.
Up to 40% of booked vaccine appointments are no-shows, health leaders have warned, as the Government said it has met its target of offering every adult a booster jab by the end of the year.
The Department of Health and Social Care (DHSC) announced on Friday that it had met the goal set by the Prime Minister to ensure all eligible over-18s in England had the chance to get their vaccines by December 31.
It is understood this is based on the take-up of boosters and those eligible being contacted.
The NHS Confederation said it was “encouraging” to see people coming forward for their jabs, but it had heard reports that some vaccination clinics were only a third full as cases of the Omicron variant continued to rise rapidly.
Chief executive Matthew Taylor said some primary care leaders had told the organisation that people were not turning up to as many as 40% of their booked appointments.
“It is encouraging to see people still coming forward for their first and second doses, as well as the massive achievement on boosters,” he said.
“However, cases of Omicron are rising rapidly… Health leaders are worried about the level of illness and demand that their staff across the NHS could have to respond to in January and so, it is vital that everyone who is eligible takes up the offer of a jab or booster shot.
“Some primary care leaders are telling us their vaccination clinics are only a third full and that people are not turning up to as many as 40% of their booked appointments.
“While walk-ins continue to be on offer, they are calling on people to stick to their scheduled vaccine appointments and if they can’t for whatever reason that they cancel with notice as this will help manage pressures, particularly given the staffing crisis we are facing currently.”
Health Secretary Sajid Javid said he was “delighted” to confirm the booster target had been hit.
“I am incredibly proud of the work the NHS has done to accelerate the programme and offer my thanks to the frontline staff, volunteers, Armed Forces and British public who have made it possible for us to meet this commitment,” he said.
Shadow health secretary Wes Streeting said: “While eagle-eyed observers will note that the Prime Minister shifted the goalposts on what he actually promised to deliver, this should not detract one bit from the fact that the NHS has pulled off an unprecedented number of vaccinations in recent weeks.
“Everyone involved should be enormously proud of what they’ve achieved, from volunteer vaccinators through to members of our armed forces drafted in to help.
“I urge everyone who has yet to receive their first, second or booster jab to book without delay.”
The Government set a target at the end of November to offer a booster jab to everyone eligible aged 18 and over by the end of January 2021.
But this goal was subsequently brought forward by a month in response to the emerging threat of the new variant sweeping across the country.
Boris Johnson said on December 12 that it was clear two doses of the vaccine were “simply not enough” to give the level of protection needed and that, without a boosted population, the NHS could be overwhelmed.
He therefore set a new deadline of offering every adult in England a booster by December 31.
The Welsh Government also announced on Friday a booster vaccination appointment had been offered to every eligible adult in the country.
More than 1.5 million boosters have been administered in Wales, with 81% of over 50s and 70% of eligible people aged over 12 receiving their third jab.
Health minister Eluned Morgan said: “The response from the public has been outstanding and we want to thank everyone who kept their appointment and accepted the offer of their booster.
“A huge thank you also goes to our NHS Wales teams, their partner organisations and all volunteers who have worked tirelessly through such a busy time to deliver this monumental task.”
The NHS national booking system was opened to all people over the age of 18 on December 15.
According to analysis by the PA news agency, around 63% of all adults in the UK have now received a booster or third dose.
A total of 435,293 booster and third doses of Covid-19 vaccine were reported in the UK on Wednesday, the highest daily figure since December 23.
More than 33.5 million booster and third doses have now been delivered in the UK, with 1.8 million in the past seven days.
The figures have been published by the UK’s four health agencies.
As part of the scaled-up delivery, the DHSC said 180 new vaccination sites were opened in December, including at football stadiums, shopping centres and at Christmas markets.
It added that over 30 million people had been sent booking invites from the NHS in 2021, including over 3.9 million letters, 26.7 million text messages and 14.7 million emails.
Anyone who has not yet received the vaccine is now being urged to come forward to curb the spread of the disease.
Dr Emily Lawson, head of the NHS Covid-19 vaccination programme, said: “With Covid-19 cases continuing to rise rapidly, the best resolution you can make this new year is to protect yourself and those around you, so I urge you to come forward for your booster as soon as you can, and with hundreds of thousands of appointments available in the coming days, it has never been easier to grab your jab.”