Significant medical advances have transformed HIV from a fatal diagnosis into a manageable chronic condition. While a definitive, sterilizing cure remains elusive, a functional cure has been achieved in rare instances in infants. Progress focuses on preventing the transmission of the virus from mother to child—known as perinatal transmission—and aggressively treating the virus in newborns who become infected. This work relies on precise terminology and the rapid deployment of potent antiretroviral therapies.
Preventing Mother-to-Child Transmission
Perinatal transmission occurs when HIV passes from a mother to her baby during pregnancy, childbirth, or through breastfeeding. Without intervention, the risk of transmission ranges from 25 to 30%. Due to widespread testing and treatment protocols, this rate has been dramatically reduced to 1% or less in the United States and Europe.
The prevention strategy begins with antiretroviral therapy (ART) for the mother during pregnancy and delivery. Effective ART suppresses the mother’s viral load—the amount of HIV in her blood—often to undetectable levels, which drastically lowers the risk to the fetus. A cesarean section may also be recommended if the mother’s viral load is high near the time of birth, minimizing the infant’s exposure to the virus in the birth canal.
After birth, the newborn receives prophylactic antiretroviral medication, ideally within six hours of delivery. The regimen depends on the mother’s viral load status, typically consisting of zidovudine (ZDV) for low-risk infants or a combination of two or three drugs for those at higher risk. This temporary treatment prevents any virus that entered the baby’s body during delivery from establishing a lasting infection. Since HIV can be transmitted through breast milk, mothers in resource-rich settings are advised to use formula, while others may be advised to breastfeed with strict adherence to ART.
Standard Treatment for HIV-Positive Infants
For the small number of infants who acquire the virus despite prevention efforts, the standard of care requires immediate and aggressive treatment. Pediatric HIV is diagnosed using specialized viral diagnostic tests that look for the virus’s genetic material, rather than the antibodies used for adult testing. This is necessary because newborns can temporarily carry their mother’s HIV antibodies even if they are not infected.
Once the virus is confirmed, the infant is immediately started on combination antiretroviral therapy (cART). This regimen typically involves three antiretroviral drugs working together to block viral replication at multiple stages. The goal of this aggressive, early approach is to suppress the virus quickly, minimizing damage to the developing immune system and preventing the progression to Acquired Immunodeficiency Syndrome (AIDS).
While cART is not a cure, continuous use can reduce the viral load to an undetectable level, allowing the child to live a long, healthy life. These medications must be taken exactly as prescribed, often for life, to maintain control over the infection. The necessity of lifelong medication for chronic viral suppression distinguishes this standard treatment from the pursuit of a cure.
Understanding the Functional Cure Concept
A “functional cure” in infants refers to long-term remission where the virus remains suppressed without the need for ongoing daily medication. Researchers hypothesize that this may be possible in newborns because the HIV reservoir—the hidden, dormant pool of infected cells—has not yet been fully established. The strategy involves administering high-dose, combination ART within hours or days of birth, before the virus embeds itself deeply into the immune system’s memory cells.
This approach was famously attempted in the case of the “Mississippi Baby,” who received a three-drug regimen just 30 hours after birth. Treatment was stopped by the mother at 18 months, and the child remained virally suppressed for over two years without medication, leading to the initial declaration of a functional cure.
However, the child’s viral load became detectable again at age four, confirming the virus had rebounded. This outcome underscored the difficulty in eliminating the viral reservoir entirely. A similar strategy was applied to a second infant in California, but doctors did not stop the medication to test for remission, illustrating the caution surrounding this experimental approach.
Distinguishing Cure, Remission, and Viral Suppression
The terminology used in HIV treatment reflects different levels of success against the virus. The most common outcome is viral suppression, meaning the amount of HIV in the blood is reduced to a very low level (fewer than 200 copies per milliliter). When the viral load is so low that a standard lab test cannot detect it, this is referred to as an undetectable viral load. Maintaining this requires continuous, daily medication (ART) because the virus is still present in the body, hiding in the viral reservoir.
Remission, often termed a functional cure, is a much rarer outcome where the virus remains undetectable even after a person has stopped taking ART. In this state, the body’s natural defenses control the remaining viral particles without medication, preventing the disease from progressing. The virus is clinically controlled but not completely eliminated.
The ultimate goal, a sterilizing cure or definitive cure, involves the complete eradication of all replication-competent HIV from the body. This has only been achieved in a handful of adults who received complex, high-risk bone marrow transplants for cancer. Since this procedure is too risky and complex for the general population, the functional cure remains the primary focus of pediatric research.