There is confusion over when surgeries in the region can begin offering coronavirus jabs to under-50s after one practice was told it did not have permission.
The Humbleyard Practice, based in Cringleford, has been instructed not to vaccinate anyone in priority group 10 until the next phase of the rollout has officially started.
Cohort 10 includes around 21 million people aged 18 to 49 with no existing medical conditions, and will begin with those in their 40s.
Some patients from the cohort have already received jabs in Norfolk and Waveney, as well as elsewhere in the country, despite not having health conditions.
Updating patients via Facebook, Humbleyard said it had written to health secretary Matt Hancock in a bid to move on to the next cohort ahead of schedule.
But that is now unlikely to happen until mid-April after health officials denied its request.
"Vaccination clinics will not run on Friday evening or Saturday as, despite our best efforts, there is no permission to start cohort 10," wrote Humbleyard on social media.
"Please be reassured no vaccine has been wasted, as has been our policy all the way through."
The practice added that 500 existing appointments on Friday (March 26) would still be going ahead.
A woman in her 60s, who has been volunteering at Humbleyard since January, said having to postpone clinics was "very sad".
She added: "I cannot work it out because, in some places, under-50s are already being done.
"Maybe they want to get everyone on a level playing field. Perhaps Humbleyard is a victim of its own success.
"The rollout is at the point where we just want to get it out there as soon as possible."
Clarifying its position, Norfolk and Waveney Clinical Commissioning Group (CCG) said it was awaiting permission of its own from decision-makers.
A spokesman said: "We can only open vaccination clinics to people under 50 when we are given permission from NHS England, the government and the JCVI.
“For the time being, we need to focus on ensuring we have vaccinated as many people from cohorts 1 to 9 as possible. All of our efforts are, for the time being, focused on that.
“As soon as we are able to vaccinate patients from cohort 10, we will book them in."
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