All staff, patients and visitors must continue to wear face coverings in Oxfordshire's hospitals despite restrictions easing further on Monday 19th July.
Oxford University Hospitals NHS Foundation Trust, which runs the John Radcliffe and Horton General, says social distancing and hand hygiene guidance will remain in place.
The trust says it is to protect vulnerable patients from Covid-19 and to prevent possible staff shortages due to self-isolation.
Professor Meghana Pandit, Chief Medical Officer at Oxford University Hospitals NHS Foundation Trust, said: "In our hospitals we care for the sickest and most vulnerable patients, and we must do everything possible to keep them safe.
"Even if you have had two vaccinations, you can still carry and pass on COVID-19 to others. We are therefore asking visitors and patients coming to our hospitals to continue to follow the guidelines, wear a face covering, follow social distancing guidance and use good hand hygiene."
It follows concerns for the rising number of cases of coronavirus within Oxfordshire.
Recently, Oxford city was given rapid additional support by central government including increased testing and help to maximise vaccine uptake, as cases rose to 'unprecedented' levels.
The city is firmly in the top ten in the entire country having risen particularly rapidly during late June and early July.
Patients, visitors and staff are being asked to:
Wear a mask at all times (unless exempt)
Use sanitiser or wash your hands for 20 seconds
Maintain 2 metres distancing
Keep left in corridors
Adhere to the signs showing the maximum number of people in a room/lift
Don't use seats that are taped off
Observe visiting rules