"Is it the breakthrough case of the year? Not necessarily," Fauci said. "First of all, you always need to replicate something multiple times. With a single case, you always have to take it with a grain of salt.
"The fact remains that it's important proof of a concept that deserves further study," he said.
Although the child is not on HIV medication now, that doesn't mean symptoms won't return, said Dr. Myron Cohen, director of the Institute for Global Health and Infectious Diseases at the University of North Carolina at Chapel Hill, who was present at the conference where the "cure" was announced.
"We desperately want to cure the infection," Cohen said. "There's no doubt about our commitment. The big hole is, of course, only massive amounts of time will say whether this child is not infected."
Kline, who has treated children with HIV and AIDS since the 1980s, said calling this a cure, even a functional cure, sends the wrong message to the rest of the world by giving people false hope. It's possible that the child was one of a handful of patients who were born with HIV and were somehow able to control the virus on their own, Kline said.
One of Kline's patients, who is now 22 years old, initially tested positive for HIV and then tested negative just before he started treatment. The patient's test results waffled from positive to negative, and Kline found that he was infected with HIV, but the virus remained dormant most of the time. As such, the patient doesn't need treatment.
"These are unusual cases, and I do think we have something to learn from them, but to say this baby was 'cured' because we gave him powerful medications in the first 30 hours of life, I think that's a real stretch," Kline said.
Since Sunday's announcement, Kline said he's been bombarded with calls and emails from around the world from people who want to know whether the standard of care for HIV patients should change or whether they should explore stopping therapies for some patients.
"I think we've done a real disservice," Kline said. "We might cause some practitioners to erroneously think that now they should be treating every single baby born to a mother with HIV with potentially toxic medication. We're experimenting on babies who, in many cases, are not even infected with HIV."