"The real question will be what percentage of babies treated early will achieve this result? We don't know," he said.
Fauci believes this kind of outcome only becomes important if you have a considerable proportion of babies protected, making it applicable as a potential therapy approach.
"You always get an outlier," he said. In this case, the outlier being the 9-year old. "Further study is needed to learn how to induce long-term HIV remission in infected babies," Fauci said.
Violari agrees that this new remission case is not applicable to all infants with HIV, but instead that something unique about his biology and immune system helped him protect himself from the virus, aided by starting treatment early.
He developed an effective immune response to the virus early on, she said, and treatment then protected the child. "I think the early treatment aided it," she said.
Her team now hopes to investigate the child, and others from the original CHER trial along with HIV-negative children to try to elucidate just what is unique about the biology enabling a child who has been treated to then suppress the virus indefinitely -- and independently -- known as a post-treatment controller.
"We need to see where the differences lie," she said, adding that this insight could be used to inform vaccine design or new treatment approaches, such as the use of neutralizing antibodies to help people suppress the virus.
We could develop a product given to people in combination with ART so people can eventually stop ART, said Violari. This would not be because they are cured, but because virus levels are low enough, or undetectable, to help them stay healthy without the need for drugs.
"It's a long shot," Violari said. "But we can look at what's different."
Fauci agreed that extensive evaluation of immune regions of these cases could help scientists find something special to guide inducing this in others. "That's being intensively studied now," said Fauci. "We have the outcome, we just need to get there."
Hope for future HIV control
"We are delighted and excited by what happened with this child ... we need to extrapolate (from this) to the benefit of other children on antiretroviral drugs," said Dr. Mark Cotton, professor of pediatrics at Stellenbosch University in South Africa, who co-led the study. "Africa is still the epicenter of the epidemic and more babies are acquiring HIV than anywhere else."
Cotton hopes his team presenting these results will boost morale, both among cure researchers and those managing treatment programs for children across the continent.
Dr. Deborah Persaud, professor pediatrics at Johns Hopkins University School of Medicine in the United States, agreed this discovery will become useful in terms of treating HIV-infected infants.
"This offers hope for the field," she said. "Every case like this keeps optimism around perinatal infection."
Persaud is part of team that reported the case of the Mississippi baby in 2013 and continues to care for the child and track progress.
She agreed with Violari's team that there is something unique about the South African child's biology, because their viral levels began coming down even before the child received treatment. "This suggests there was an immune mechanism at play here," she said. "Somehow, there was early control of the virus."
The three cases to date all form part of this era in which rare examples of remission are coming to light and providing valuable insight for HIV cure researchers. They serve as proof of concept that this can occur, she said, stressing that this is far from the norm.
"Many kids around the world have been treated early and are not off treatment," she said.
A current trial, known as IMPAACT P1115 and funded by the US NIH, is providing treatment to HIV-infected infants within 48 hours of birth, further exploring options to eventually enable children to come off ART, even if just for a few months at a time, and investigate the potential for remission.
Almost 400 infants have been enrolled across nine countries. The first cases might be eligible to stop ART later this year, according to the NIH.
While Persaud said remission cases are likely to be the exception to the rule, she added that the long-term hope is to go from the need for daily ART, which involves potential toxicity and the need for adherence, to children being able to come off treatment for extended periods.
Even not taking drugs for three months of life, some adults say is a big step for them, she said. "This can make living with HIV less burdensome ... and just make life a lot more livable."