Between 10 and 15 Covid patients are now being admitted to the Queen Elizabeth Hospital each day, amid a sharp rise in cases.
The King's Lynn hospital said it is currently treating 120 people with coronavirus.
While most do not require intensive care, staff said the increase was having a knock on effect on services.
It comes after restrictions such as mask wearing were relaxed by the government, as the nation moves to a new phase of the pandemic.
But visits remain on hold at the hospital apart from those seeing children or patients for compassionate reasons. Outpatients are being asked to attend alone.
Chief nurse Alice Webster said: "In the best interests of our patients, the local community and our staff, to ensure everybody's safety, we will not be relaxing our visiting restrictions any further at this time – in line with the other trusts across Norfolk and Waveney.
"In addition, we have also taken the difficult decision to cancel the in-person celebration of our staff awards, due to take place on Thursday, to reduce risks to our patients and staff. We will, along with the other trusts in Norfolk and Waveney, be keeping this under regular review and make changes to the current restrictions as soon as it’s safe to do so."
A system of 'compassionate visiting' is in place for those who are receiving end of life care or those with additional needs.
The hospital is continuing to offer contact for patients and their loved ones via smartphones and tablets, while its family liaison officers are ensuring patients' families and loved ones are easily able to contact wards.
They can be contacted on 07909 39792 or 07909 395415 seven days a week between 8.15am and 7.45pm.
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