Without any medical intervention for the past 8½ years, a 9-year-old South African child remains free of the HIV infection that was acquired at birth. This is only the third case worldwide of HIV driven into full remission in a child.
HIV is a virus that gradually attacks the body’s immune system. Transmitted through infected bodily fluids like blood or semen, the virus enters the bloodstream and targets the host’s helper T cells, a specialized type of white blood cells. Because it is a retrovirus, HIV can hijack the host’s replication machinery to make more of copies of itself.
It’s estimated that the virus can make up to 10 billion new copies every day. The onslaught of viruses damages the immune system, leaving patients vulnerable to a host of infections. This is the AIDS (acquired human immunodeficiency syndrome) part of HIV/AIDS.
The child was treated shortly after the HIV diagnosis at one month old, as part of the Children with HIV Early Antiretroviral Therapy (CHER) trial. Three-hundred and seventy children were enrolled in the trial, and were randomized to receive anti-retroviral therapy (ART) for 40 weeks or 96 weeks. In a third group, children received treatment according to the standard practice at the time, which did not include immediate therapy.
Out of all the children in the study, the anonymous 9-year-old child was the only one whose viral count was undetectable in the blood. Retrospective blood analysis showed that the child achieved remission shortly after the therapy was initiated.
"This is really very rare," said Dr. Avy Violari, head of pediatric clinical trials at the Perinatal HIV Research Unit at the University of Witwatersrand in South Africa. The other case of “cured” HIV occurred in a Mississippi baby girl who received ART from birth to 18 months, and subsequently achieved remission for almost a year. The third case occurred in a French baby girl who also received treatment at birth. She stopped treatment at age 6 when blood tests revealed no trace of HIV. At 20, she is the oldest child cured of HIV.
Because HIV remission only occurred in one child in the study, and is only the third case worldwide, researchers suspect there are other unknown immunogenic factors at play. "We don't believe that antiretroviral therapy alone can lead to remission,” said Dr. Violari. "We don't really know what's the reason why this child has achieved remission - we believe it's either genetic or immune system-related."
Coincidentally, evidence to support this immunogenic hypothesis can be found elsewhere in South Africa. A study in late 2016 revealed that 1 in 10 South African children may have a natural “monkey-like” immune system that lets them beat out AIDS caused by HIV. In this subset population (170 children), scientists show the children are unequivocally positive for HIV infection, yet somehow have never had AIDS despite any antiretroviral therapy. Scientists in this study hypothesize that instead of attacking the HIV and losing, the immune system in these children adopt a “keep calm and carry on” approach, which could counterintuitively suppress the virus’ destruction.
It’s important to note that while no other children in the study achieved remission, receiving ART early had a significant effect on mortality rate. In both groups that received immediate ART for 40 or 96 weeks, mortality decreased by 76 percent, and HIV disease progression slowed by 75 percent. Unique cases like these and others provide researchers with important clues on how we can achieve functional HIV cures.