The girl, who has not been identified, was just two months old when she started on HIV drugs.
But 40 weeks later she stopped taking them as part of a medical trial.
Tests were carried out when she was nine-and-a-half years old found signs of virus in a small number of immune system cells, but none that were capable of reproducing.
The girl does not have a gene mutation that gives natural resistance to HIV infection, Fauci said, so her remission seems likely due to the early treatment.
Her case provides more evidence that early treatment can occasionally cause a long remission that, if it lasts, would be a form of cure.
The South African’s story was revealed at an AIDS conference in Paris this morning, where researchers also gave encouraging results from tests of shots administered every month or two instead of daily pills to treat HIV.
‘This new case strengthens our hope that by treating HIV-infected children for a brief period beginning in infancy, we may be able to spare them the burden of life-long therapy,’ said AIDS expert Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases (NIAID) which funded the study.
Some scientists refer to sustained, drug-free remission as a ‘functional cure’.
Unlike a traditional cure, where the virus is eradicated, the patient still has HIV in their system but it is so weakened that it cannot replicate or spread to sexual partners.
Current treatments keep HIV under control but must be taken lifelong. Only one person is thought to be cured – the so-called Berlin patient, a man who had a bone marrow transplant in 2007 from a donor with natural resistance to HIV.
But transplants are risky and impractical to try to cure the millions already infected. So some researchers have been aiming for the next best thing – long-term remission, when the immune system can control HIV without drugs even if signs of the virus remain.
Aggressive treatment soon after infection might enable that in some cases, and the South African girl is the third child who achieved a long remission after that approach.
The other two people who went into remission are:
A French teen who was born with HIV and is now around 20 has had her infection under control despite no HIV medicines since she was roughly 6 years old.
A Mississippi baby born with HIV in 2010 suppressed her infection for 27 months after stopping treatment before it reappeared in her blood. She was able to get the virus under control again after treatment resumed.
At least a dozen adults also have had remissions lasting for years after stopping HIV medicines.
A study underway now is testing whether treating HIV-infected newborns within two days of birth can control the virus later after treatment stops. It started in 2014 in South America, Haiti, Africa and the United States, and some of the earliest participants might be able to try stopping treatment later this year
Dr Michael Brady, Medical Director at Terrence Higgins Trust, said: ‘This case report is really interesting in the sense that it adds to our knowledge of what might be achievable with very early treatment in infants.
‘Early HIV therapy, in both children and adults, has been shown to reduce some of the damage to the immune system that HIV causes in the first few weeks and months of infection.
‘If we can understand this mechanism better it will hopefully lead to novel treatment strategies and, maybe one day, a cure. Further research is needed, but this case adds to the hope that, one day, we may be able to prevent the need for life-long therapy with a short course of early HIV treatment in infancy.
‘For now, however, early diagnosis and life-long treatment for HIV remain our best options for fighting the epidemic.’
Treatment might get easier if two large studies underway now confirm results reported Monday from a study testing a long-acting combo of two HIV drugs – Janssen’s rilpivirine and ViiV Healthcare’s cabotegravir.
Cabotegravir is experimental; rilpivirine is sold now as Edurant and used in combination with other drugs for treating certain types of HIV patients.
After initial treatment to get their virus under control, about 300 study participants were given either daily combination therapy pills or a shot every four or eight weeks of the long-acting drug duo to maintain control.
After nearly two years, 94 percent on eight-week shots, 87 percent on four-week shots and 84 percent on daily pills had their infections suppressed, with similar rates of side effects.
‘The results were good regardless of whether people came monthly or every two months for their treatment. This has important policy implications,’ said Dr. Linda-Gail Bekker, deputy director of the Desmond Tutu HIV Centre at the University of Cape Town in South Africa, and a co-leader of the conference.
The study was sponsored by the drugmakers. Results were published in the British medical journal Lancet.
Two large studies aimed at winning approval to sell the treatment are testing the monthly shots. Janssen said in a statement that good results from eight-week shots warrant reconsidering the longer approach.
If it works, ‘this will have a huge impact on how we manage that very important group of people who are not able to access and take drugs on a day-to-day basis,’ such as those with mental health or drug abuse problems, said Dr. Steven Deeks, an AIDS specialist at the University of California, San Francisco.