Scientific Pragmatism in “Functional Cure” for HIV

Jessie Cannizzaro '12 performs
Photo by Elèna Ruyter '14

An amazing piece of news this past week has been the announcement of a breakthrough in HIV treatment: a two-and-a-half year old girl from Mississippi has been declared “functionally cured” of HIV, after being diagnosed with the retrovirus at birth. The child, who underwent eighteen months of retroviral therapy after birth, has been off all medication for five months and shows no detectable amount of HIV in her blood. This is the first time a retroviral therapy has completely cured an HIV patient and the first time a child with HIV has ever been cured. If this treatment is effective on all infected infants, this could lead to a global breakthrough in HIV treatment.

The girl’s mother was diagnosed as HIV positive after appearing at a Mississippi hospital in premature labor. She had received no prenatal care, and was not being treated for her HIV while she was pregnant. Doctors sent the newborn to the University of Mississippi Medical Center to receive treatment almost immediately. Within 36 hours, the infant had begun a strong drug regimen to fight off the virus.

The most important element in this case is likely speed with which the infant began receiving treatment. The decision to treat the infant was based off of the mother’s blood test results, which tested positive for the HIV antibodies present in individuals affected with the retrovirus. The standard approach to treat infants infected with HIV has been to wait until blood tests on the infant have shown signs of the virus — a process that can take six weeks or longer.

Physicians hypothesize that the quick initiation of therapy in this newborn helped to prevent the build up of HIV reservoirs, or clusters of dormant HIV cells that subsist within the human immune system. These reservoirs can remain dormant for years, and modern medicine has no way to target the retroviral cells in this state. As a result, it has been impossible for medical researchers to develop drugs that can completely wipe out the HIV in an infected patient’s system, and thus there are always a supply of HIV viruses present in the body that become active as soon as retroviral therapy is stopped.

It is important to note that scientists believe the drug therapy offered to this infant did not wipe out HIV reservoirs, but rather stopped them from accumulating in the first place. Thus, if replicable, this therapy would only serve as a cure for newborns that can begin treatment almost immediately after birth. It is not a solution for the millions of children and adults already infected with HIV/AIDS, and or for the thousands of infants in developing countries born with HIV but without speedy access to an equipped medical facility. Of the 300,000 babies a year born with HIV, most come from developing areas of the world.

Although this finding is amazing news and a surprising breakthrough in a thoroughly researched field, it is striking how slight a change in treatment plan led to it. The pragmatism of the attending physician at the University of Mississippi Medical Center to begin treatment before receiving test results of the infant made all the difference. The infant was also placed on a much stronger regimen of drugs from the beginning than is typically done. When test results finally came back, the girl did, in fact, tested positive for HIV, and measurable traces of the virus were present at days 7, 12, and 20 as well. At day 29, the infant was shown to be clear of HIV, meaning that if there were still viruses in her system they were in their dormant state. Infants treated in the standard way would have been infected with the virus for months before they reached this state, which would have been long enough for them to remain infected for the rest of their lives.

A great deal of science is conducted in very structured and regimented ways, especially medical research because it is conducted on human subjects. However, this case proves there is a place for pragmatism in the sciences — even small adjustments to a standardized methodology can lend powerful scientific insights. Doctors and scientists should be free and encouraged to propose novel approaches to old scientific problems — be it through changing the models and variables of an experiment or directly challenging an old set of assumptions that may be flawed. Doctors assumed therapy should not be started until the presence of HIV in an infant could be definitively proven, but given a situation where the infant was very likely to have contracted HIV in utero or during birth, University of Mississippi doctors prescribed an aggressive treatment and in doing so saved a life.

There are many implications for what this breakthrough could mean for global heath. The most ambitious reporters and scientists are calling this a game-changing breakthrough for public health. However, it’s probably too early to go that far. The infant in Mississippi was an exceptional case before she was ever cured of HIV: the baby had very low amounts of the HIV virus in her system in early blood tests, and her treatments ended unexpectedly when the mother stopped bringing her in to her doctor. Further studies are needed to determine whether this treatment works on other infants more seriously infected, and precisely how long it takes to wipe out the virus using a strong drug regimen. Furthermore, this baby was born in the resource rich country of the United States, where testing and the beginning of treatment could be carried out in a matter of days. Most infants born with HIV are from developing parts of the world, and mothers may not have the same medical resources available to them. Prenatal treatments available to mothers who have been diagnosed with HIV have proved to be very effective in preventing transmission to the infant, and may continue to be the best option for preventing the passage of HIV from mother to child.

Nonetheless, the story of this two-and-a-half year old from Mississippi is thrilling and rich in scientific questions one can draw from it. As HIV research advances and new treatment options are explored, thousands more will benefit from the aggressive treatment plan that functionally cured this child.

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