Nurse Pauline Cafferkey has arrived at the Royal Free Hospital in London for treatment for a "late complication" from the Ebola virus.
Ms Cafferkey, 40, was flown from Glasgow by RAF Hercules to RAF Northolt before being transferred to the hospital which has the UK's only high level isolation unit.
It is the third time the medic from South Lanarkshire has been treated in hospital since contracting Ebola in Sierra Leone in December 2014 at a Save the Children treatment centre.
On Tuesday NHS Greater Glasgow and Clyde said Ms Cafferkey was in a stable condition after "routine monitoring" identified a problem.
Medical staff and RAF personnel were involved in moving her on to the aircraft in an isolation tent at Glasgow airport on Tuesday afternoon.
She was transferred to the Royal Free from the Middlesex RAF base in a convoy of two ambulances and police vehicle - arriving in the capital shortly before 6pm.
A spokesman for the Royal Free Hospital said: "We can confirm that Pauline Cafferkey is being transferred to the Royal Free Hospital due to a late complication from her previous infection by the Ebola virus.
"She will now be treated by the hospital's infectious diseases team under nationally-agreed guidelines.
"The Ebola virus can only be transmitted by direct contact with the blood or bodily fluids of an infected person while they are symptomatic, so the risk to the general public remains low and the NHS has well-established and practised infection control procedures in place."
Ms Cafferkey spent almost a month in an isolation unit at the London hospital after contracting the disease the first time around.
She was released after making a recovery but fell ill again in October last year and was again treated at the Royal Free for meningitis caused by Ebola.
At one point, the Scottish nurse was described as ''critically ill'' but was discharged in November and transferred to Glasgow's Queen Elizabeth University Hospital to continue her recovery and later returned home.
When she was released from hospital for the second time, she said: ''I am forever thankful for the amazing care I have received at the Royal Free Hospital.
''For a second time, staff across many departments of the hospital have worked incredibly hard to help me recover and I will always be grateful to them and the NHS.''
At the time of her re-admission last year, Dr Michael Jacobs, from the Royal Free, described the situation as ''unprecedented'' while the World Health Organisation (WHO) said Ms Cafferkey was the only known Ebola survivor to develop meningitis months later.
In November, the Royal Free said Ms Cafferkey had made a full recovery from Ebola and was no longer infectious.
Dr Derek Gatherer, lecturer in biomedical and life sciences at Lancaster University, said: ''It is very sad to hear that Ms Cafferkey has once again been admitted to hospital.
''It is now becoming clear that Ebola is a far more complex disease than we previously imagined.
''The meningitis that Ms Cafferkey suffered from at the end of last year is one of the most serious complications of all, as it can be life-threatening. She was unlucky enough to be one of only a handful of patients in whom it has been seen."
Scotland's Health Secretary, Shona Robison, said: "Our thoughts are with Pauline Cafferkey and her family and friends today.
"I'd like to thank the expert NHS staff in Glasgow who have looked after her and helped with her transfer to the Royal Free Hospital, where Pauline has been treated before and where clinicians agreed it would be best to continue her treatment.
"We have been in close touch with NHS Glasgow and Health Protection Scotland and are reassured that the risk to the general public remains extremely low and that the NHS in Scotland has well established and practised infection control procedures in place."
The WHO declared the Ebola outbreak over last year after the deaths of thousands of people but two new cases emerged in Sierra Leone in January. The organisation called for a ''critical period of heightened vigilance''.