A child born to an HIV-infected mother in Mississippi may be cured after a swiftly administered course of drugs. A number of factors make the child’s case unique, however, and clinicians caution that we have not discovered a general cure for HIV yet. Still, the medical first may hint at ways to fight the AIDS-causing virus.
An HIV cure has been elusive because the virus has ways of hiding within the body. It can secret itself into blood cells and other so-called reservoirs. Faced with powerful drugs that prevent viral replication, called antiretroviral therapy (ART), HIV levels in the blood drop down to nearly undetectable levels. Take the pressure off by halting treatment, however, and the virus comes roaring back.
Recent years have offered some hints about how to disable HIV’s assaults. A rare category of individuals, dubbed “elite controllers” can drop the drugs and still show no symptoms. Also, researchers are developing a treatment that will eliminate one of HIV’s entryways into immune cells through a gene-editing process. Yet, the best approach already available is to prevent infection, a daunting challenge despite decades of progress.
Preventing infection in the very young is a priority. Every day, approximately 1,000 babies are infected around the world with HIV during gestation, birth or breast-feeding, according to the United Nations Children’s Fund. Typically, newborns at risk of contracting HIV may receive one or two antiretroviral drugs prophylactically. If at six to eight weeks of age the baby tests positive for the viral antibodies, the physician will switch to the therapeutic cocktail and doses. The baby from Mississippi received a combination of the drugs zidovudine, lamivudine and nevirapine, just 30 hours after birth.
This aggressive treatment is not typical because antiretroviral drugs are toxic and infection is not always certain. The mother passes HIV antibodies on to her child during gestation. Only after six to eight weeks of life can clinicians tell whether the baby is actually infected with HIV and not simply carrying the mother’s antibodies. “These drugs are not like vitamins,” says Lynne Mofenson, chief of the Maternal and Pediatric Infectious Disease Branch at the National Institute of Child Health and Human Development. “You only use them when the child is at high risk.”
Current guidelines in the U.S. recommend that expectant mothers who are infected with HIV receive drugs during pregnancy. Then, babies should be delivered via cesarean section and be formula-fed. Those recommendations can minimize the risk of transmission to less than 1 percent Mofenson says. Accordingly, mother-to-child transmission of the virus is rare in developed nations but much more common where anti-HIV drugs are scarce. Currently, fewer than 200 children in the U.S. are born HIV-positive each year.
The mother in the new case did not receive any prenatal care or ART. She arrived at the clinic in labor and delivered her baby prematurely (at 35 weeks into her pregnancy). When a test came back showing she was HIV-positive, University of Mississippi Medical Center pediatric HIV specialist Hannah Gay determined that the risk to the child was great. Therefore she decided to treat, even though clinicians hadn’t confirmed that the baby was infected.