Flu vaccine deliveries will be delayed by "up to two weeks" due to a shortage of HGV drivers, as ministers are facing calls to "get a grip" on the crisis.
Appointments for many patients will have to be rescheduled after Seqirus, the largest provider of flu vaccines to the UK, confirmed delays of up to two weeks in England and Wales.
The company blamed “unforeseen challenges linked with road freight delays” for the delivery disruption.
GP Online reported the company had sent a letter advising practices not to rebook appointments until they receive confirmation of a new delivery date of vaccine supplies.
An apparent exodus of HGV drivers from EU countries, who returned to the continent during the coronavirus pandemic and remained there, has been blamed for disruption in sectors of the economy in recent weeks.
For Labour, Shadow Health Secretary Jon Ashworth said: “GPs are at their wits’ end, first forced to cancel blood tests because of bottle shortages and now we learn flu vaccines will be delayed.
“This has been a summer of crisis for the NHS with patients paying the price.
“With winter coming and flu resurgence a huge risk, ministers must urgently get a grip.”
A Seqirus spokeswoman said: “Seqirus supplies influenza vaccines to all GP practices in England and Wales.
“Due to unforeseen challenges linked with road freight delays, we have informed all our customers of a consequent delay to their scheduled vaccine delivery by a maximum of one to two weeks.
“Seqirus is working hard to resolve the delay to allow customers to reschedule their influenza vaccination clinics.”
Dr Richard Vautrey, British Medical Association GP committee chairman, said the issue is likely to affect a “significant proportion” of practices – and have a “serious impact” on practice workloads and patients.
He said: “Many practices will have spent the last few days and weeks meticulously planning for their flu vaccination programme, inviting and booking patients in for their jabs, only now to have to contact them all again to cancel or reschedule appointments.
“This causes a huge increase in staff’s already unsustainable workloads, and inconvenience and unneeded anxiety for patients who will be keen to be protected ahead of winter."
Flu immunisation is particularly important this year, the deputy chair of the Joint Committee on Vaccination and Immunisation (JCVI) has said.
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Professor Anthony Harnden told BBC Breakfast: “Clearly influenza immunisation this year is really important and the reason it’s so important is because of lockdowns, we’ve had very low circulating influenza levels last winter. “So we do know when there are low circulating influenza levels the year before, often we get high infection rates in the following year so it’s quite possible that we’ll have a high instance of influenza this year."
Health Secretary Sajid Javid has previously said the seasonal flu programme in England – beginning this month – will be the biggest in the country’s history and urged everyone eligible to take up the jab.
The free flu vaccines will be available to more than 35 million people including all secondary school students this winter, according to the government.
It comes as the country prepares to deal with a normal flu season alongside the Covid pandemic.