A number of Covid vaccine clinics have been cancelled following a sudden influx of patients booking appointments in advance.
The Old Law Courts, in Lowestoft, and King's Lynn Corn Exchange had been due to offer jabs to people in priority groups on a drop-in basis on Wednesday (April 14).
But the one-off sessions had to be called off after a surge in bookings meant a drop-in service could no longer be offered.
And Norfolk and Waveney CCG, which is leading the local rollout, said further clinics scheduled in Attleborough (Connaught Hall), Downham Market (town hall) and Harleston (old Paddock Road surgery) would no longer take place on Thursday and Friday.
A spokesman for the CCG said: "Due to an influx of bookings for COVID-19 vaccinations, no further drop-in clinics will take place in Norfolk and Waveney this week as all available slots are now fully booked.
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“A review of drop-in clinics for the weekend ahead will take place later this week and we plan to announce further drop-in appointments shortly.
“Vaccine appointment availability can vary depending on demand and vaccine supply, so please be patient and keep checking as appointments are regularly added to the booking system.
"Alternatively, eligible patients can contact their GP practice to ask for an appointment.”
This week's cancelled clinics were due to be held at venues already being used as large-scale centres, at which appointments can be booked online.
This week has seen a sharp rise in bookings at mass vaccination sites after the offer of a vaccine was extended to over-45s, many of whom are now being offered the Moderna product.
They are being encouraged to use the online portal, which is also open to over-50s, those at high risk from coronavirus, people with learning disabilities, and paid or unpaid carers.
But, amid a shortfall in vaccine supply throughout April, health bosses are battling to juggle 45 to 49-year-olds with an increasing number of older patients in need of second doses.
Drop-in clinics with no appointment necessary were launched last month in a bid to immunise everyone over the age of 50 in Norfolk and Waveney.
Around 96pc have already received initial doses, but officials are keen to get the figure closer to 100pc.
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