There's no guarantee the child will remain healthy, although sophisticated testing uncovered just traces of the virus' genetic material still lingering. If so, it would mark only the world's second reported cure.
Specialists say Sunday's announcement, at a major AIDS meeting in Atlanta, offers promising clues for efforts to eliminate HIV infection in children, especially in AIDS-plagued African countries where too many babies are born with the virus.
"You could call this about as close to a cure, if not a cure, that we've seen," Dr. Anthony Fauci of the National Institutes of Health, who is familiar with the findings, told The Associated Press.
A doctor gave this baby faster and stronger treatment than is usual, starting a three-drug infusion within 30 hours of birth. That was before tests confirmed the infant was infected and not just at risk from a mother whose HIV wasn't diagnosed until she was in labor.
"I just felt like this baby was at higher-than-normal risk, and deserved our best shot," Dr. Hannah Gay, a pediatric HIV specialist at the University of Mississippi, said in an interview.
That fast action apparently knocked out HIV in the baby's blood before it could form hideouts in the body. Those so-called reservoirs of dormant cells usually rapidly reinfect anyone who stops medication, said Dr. Deborah Persaud of Johns Hopkins Children's Center. She led the investigation that deemed the child "functionally cured," meaning in long-term remission even if all traces of the virus haven't been completely eradicated.
Next, Persaud's team is planning a study to try to prove that, with more aggressive treatment of other high-risk babies. "Maybe we'll be able to block this reservoir seeding," Persaud said.
No one should stop anti-AIDS drugs as a result of this case, Fauci cautioned.
But "it opens up a lot of doors" to research if other children can be helped, he said. "It makes perfect sense what happened."
Better than treatment is to prevent babies from being born with HIV in the first place.