Pauline Cafferkey has been taken from Glasgow to London by an RAF Hercules for a third stay in hospital since contracting Ebola.
The nurse is to be treated at the Royal Free Hospital for “a late complication from her previous infection”, a spokesman confirmed.
The hospital has the UK”s only high-level isolation unit used for treating infectious diseases.
Ms Cafferkey, from South Lanarkshire, was earlier admitted to Glasgow”s Queen Elizabeth University Hospital for “further investigations”.
She first contracted Ebola in December 2014 after treating patients in Sierra Leone at the height of the outbreak which killed more than 11,000 people.
She spent almost a month being treated in the isolation unit at the Royal Free and was discharged in January 2015 after it was thought she had recovered from the virus.
But on 9 October last year she was flown from Glasgow back to the Royal Free Hospital by a military plane after an “unusual late complication” caused her to fall ill again, with meningitis caused by Ebola.
Dr Derek Gatherer, from Lancaster University, previously told Sky News that people who fight off Ebola produce antibodies that “kill off the virus in most bodily fluids”.
But he added: “In areas of the body where the immune system is not particularly active – one of these is the central nervous system … the Ebola virus can survive in very small quantities.”
Also at the time of Ms Cafferkey”s re-admission last year, Dr Michael Jacobs, from the Royal Free, described the situation as “unprecedented”.
He said: “This is the original Ebola virus she had many months ago which has been inside the brain, replicating at a very low level, and has now re-emerged to cause this clinical illness of meningitis.”
At one point she was described as “critically ill” but she was discharged from hospital again in November last year, with doctors saying she had made a “full recovery”.