The announcement by U.S. researchers last weekend that a Mississippi infant has been cured of HIV is still generating excitement around the world. It's unclear, however, how and if that development will help scientists eradicate the disease. A cure has not been found.
U.S. researchers told an AIDS meeting in Atlanta on Sunday they had successfully cured the baby through an aggressive cocktail of drugs that were first administered within about 30 hours of the child's birth. When the baby was 18 months old, her mother stopped the treatments and missed several appointments. After they resurfaced, doctors tested the girl and discovered that the virus was virtually gone.
Now, 10 months after treatment was stopped, the girl has been declared "functionally cured," meaning that there are only traces of the virus's genetic material in her blood. However, doctors will continue to monitor her to see if the virus returns. The scientists did not disclose the baby's name or reason why the mother discontinued treatment.
The unique nature of the situation means that it is unlikely to lead to a major breakthrough, at least in the near future. The infant's mother learned that she had the human immunodeficiency virus when she was in labour at the hospital. Typically, expectant women with HIV take antiretroviral drugs, which dramatically reduces the possibility of transmission to the child. Because that did not occur in this case, doctors instead chose to give the infant a strong drug cocktail hours after birth to fight the virus.
While this could open up exciting treatment options for other infants and children infected with HIV, researchers say it does not mean that a cure is on the horizon. That is because they still don't know how to fight the dormant reservoirs of the virus that hide in the cells of infected individuals. These reservoirs are established after a person contracts the virus; they don't go away, even if the person is taking antiretroviral drugs. The medication can stop the virus from actively replicating and helps to stop progression. But if a person stops taking antiretroviral therapy, the latent HIV reservoirs start replicating again.
In the case of the Mississippi girl, doctors believe that because her drug therapy was started so quickly after transmission, virus reservoirs did not have the chance to form, which is why the virus is no longer detectable.
Mark Wainberg, a prominent HIV/AIDS researcher based at Montreal's Jewish General Hospital and McGill University, said her case makes a strong argument for early, aggressive treatment to help those infected with HIV. But in many cases, that may not be realistic. For instance, individuals may not learn that they are infected with the virus for months or even years.
"We need to find a way, in the vast vast majority of cases, of going after these populations of cells that represent this reservoir," he said. "That's something we still don't know how to do."
For that reason, researchers are cautious about whether the news of a "cure" will result in changes that can help others. Chil-Yong Kang, professor of virology at the Schulich School of Medicine and Dentistry at the University of Western Ontario, said he wants to understand how the cells infected by the latent virus were cleared. The girl in Mississippi "really opens that question," but doesn't provide many answers.
Until more is known, they are urging patients to proceed with caution and to continue adhering to their drug-treatment schedules. "This should not be taken by anyone to say that gee, one can have a complacent approach to how HIV is managed," said Upton Allen, chief of infectious diseases at the Hospital for Sick Children in Toronto.
At the same time, it is unclear whether the aggressive cocktail of drugs given to the infant will have long-term effects on her development. While her case may help other children infected with HIV, it's important not to dismiss the potential seriousness of side effects, Allen said.
But the work will continue, Wainberg said, so that researchers can find answers to those questions. "I really do feel that we're getting closer every single day to having a real cure," he said.