"When we consider starting any medication in any patient, we always consider the risk-benefit ratio," Gay said during Monday's press conference. "When the risk is something as serious as HIV disease, then it's worth the benefit that you may get from preventing that disease. Even though you never want to start drugs that may cause toxicities, if the benefit outweighs the risk, you do it."
So instead of a standard dose of nevirapine, Gay administered three antiretroviral drugs -- AZT, 3TC and a double dose of nevirapine – when the baby was 30 hours old, according to Dr. Deborah Persaud, who works at Johns Hopkins Children's Center and would become Gay's research colleague 18 months later, and has studied the case.
Nevirapine was given twice daily, which is the higher dose needed to treat HIV infection rather than prevent it, Persaud said.
Gay said the baby's treatment was "in no way experimental," because the drugs have been used before and are approved by the U.S. Food and Drug Administration. But Persaud said she did not know of any other cases in which a child had been treated this early with this combination of powerful drugs.
Although Gay began administering treatment-size doses, a diagnosis was not yet clear. It wasn't until several days into the therapy that Gay confirmed the baby was HIV-positive with the virologic testing initiated before treatment.
Gay learned -- and outside researchers later confirmed -- that the baby had such high viral loads that it would be "virtually impossible" for it to have had anything other than an HIV infection.
What Are the Risks of These Drugs?
In the short term, these drugs carry the risk of liver inflammation, allergic reactions, and bone marrow suppression, which can predispose the patient to other infections, Kline said.
They also may have long-term toxicities, but there is little data on the long-term effects of taking these drugs early in life, which is another reason why it worries doctors to prescribe them unnecessarily, he said.
"What if we found out one of these medicines increased the risk of developing cancer in 20 years?" Kline said. "It's one of the reasons we reserve this therapy only for infants who have confirmed infection. Then, you say to yourself, even if there are long-term effects of medication, that's unlikely to be worse than having HIV."
Gay and her colleagues operated under the assumption that the baby was infected, and it's fortunate that they made the right call, said immunologist Dr. Anthony Fauci, the director of the National Institute of Allergy and Infectious Diseases.
"You don't want to be inappropriately treating babies if they're not infected," said Fauci, a pioneer in HIV and AIDS research. "You don't want to put them at risk."
Did the Mother Give Informed Consent?
Gay said in an email that the baby's mother told her to "please do whatever you need to do to keep my baby healthy."
Because the baby wasn't part of a study, there was no need to require the mother to sign a consent form for her child's treatment involving nonstandard medication use, Gay said.
Indeed, the 2013 HIV guidelines from the National Institutes of Health indicate that added drugs beyond standard of care can be used in "other scenarios" but should "be accompanied by counseling of the mother on the potential risks and benefits of this approach."